Opinion for the Court filed by Circuit Judge ROGERS.
This is an appeal of a discovery order. In April 2003, E. & J. Gallo Winery sued WD Energy Services, Inc. (f/k/a EnCana Energy Services, Inc.) in the Eastern District of California during the pendency of an investigation by the Commodity Futures Trading Commission of the California natural gas market. Gallo alleged that WD Energy (and other energy companies) had unlawfully manipulated the California energy market in violation of state and federal laws. During discovery, Gallo sought documents from WD Energy with respect to the Commission’s investigation and settlement with WD Energy. WD Energy produced many of the subpoenaed documents, but withheld documents that it characterized as relating to the settlement with the Commission. When Gallo moved to compel compliance with its subpoena, a Magistrate Judge ruled that the withheld documents were protected by a federal settlement privilege under FED. R. EVID. 501.
Gallo also served on the Commission a third party judicial subpoena from the district court for the District of Columbia to produce the WD Energy documents in its possession. The Commission indicated it would interpose no governmental privilege in responding to the subpoena. However, WD Energy filed objections to the subpoena, arguing that Gallo was collaterally es-topped by the Magistrate’s ruling on the settlement privilege and, alternatively, that many of the documents were protected by a federal settlement privilege under Fed. R. Evid. 501. The district court rejected WD Energy’s collateral estoppel arguments, ruled that no federal settlement privilege existed under Fed. R. Evid. 501, and granted Gallo’s motion to compel the Commission’s compliance with the subpoena.
See In re Subpoena Issued to CFTC,
Upon de novo review, we hold that the Magistrate’s privilege ruling was not entitled to preclusive effect under the principle of collateral estoppel. In arguing that collateral estoppél applied to the Magistrate’s ruling, WD Energy failed to meet its burden to show that the same documents were at issue in both fora; in addition, the Magistrate’s ruling contains a potential ambiguity regarding whether the privilege issue was actually decided. WD Energy’s contention based upon the doctrine of law of the case lacks merit because the third-party subpoena enforcement proceeding was a new proceeding in a different court. We do not reach the question whether a federal settlement privilege exists under Fed. R. Evid. 501. WD Energy failed to meet its burden of demonstrating that the disputed subpoenaed documents were created for the purpose of settlement discussions and therefore would merit protection under any federal settlement privilege that the court might recognize. Accordingly, we affirm the grant of the motion to compel the Commission’s compliance with Gallo’s subpoena without reaching the merits of the district court’s ruling that no settlement privilege exists under Fed. R. Evid. 501.
I.
' [1] Orders compelling production of allegedly privileged information satisfy the
*743
three criteria for collateral review under
Cohen v. Beneficial Industrial Loan Corp.,
Although WD Energy has failed to obtain a stay of the district court’s order pending appeal, and the Commission has now produced the documents to Gallo, WD Energy’s appeal is not moot. In
Church of Scientology,
II.
WD Energy contends that .the district court erred by not applying collateral estoppel to the Magistrate’s order because all of the standards for establishing the preclusive effect of a prior judgment have been satisfied. It relies on
Yamaha Corp. of America v. United States,
First, the same issue now being raised must have been contested by the parties and submitted for judicial determination in the prior case. Second, the issue must have been actually and necessarily determined by a court of competent jurisdiction in that prior case. Third, preclusion in the second case must not work a basic unfairness to the party bound by the first determination.
Id.
at 254 (citations omitted);
see, e.g., Jack Faucett Assocs., Inc. v. Am. Tel. and Tel. Co.,
A.
The background to WD Energy’s collateral estoppel claim begins in 2002, when the Commission opened an investigation into the manipulation of California natural gas markets by a number of energy companies, including WD Energy, for violation of the Commodity Exchange Act, 7 U.S.C. §§ 9, 13b, 13(a)(2), 15 (2000). In June 2002, the Commission informed WD Energy that it was a subject of this investigation. WD Energy produced a large number, of documents in response to a Commission subpoena of January 24, 2003 and the Commission’s subsequent requests for information. WD Energy requested, pursuant to a Commission regulation, 17 C.F.R. § 145.9 (2003), that the documents it was submitting be treated as confidential under the Freedom of Information Act (“FOIA”), 5 U.S.C. § 552 (2000), which affords protection for certain privileged documents,
see id.
§ 552(b)(4). On July 28, 2003, the Commission entered into a settlement agreement under which WD Energy paid $20 million as a civil penalty.
See In the matter of WD Energy Services, Inc.,
Commission Docket No. 03-02; Comm. F.L. Rep. (CCH) ¶ 29,544,
Following the settlement, the Commission notified WD Energy of FOIA requests lodged by parties contemplating suits against a number of energy companies for documents related to the Commission’s investigation of California’s natural gas market. The Commission asked WD Energy to provide a “detailed written justification” of its previous requests for confidential FOIA treatment. By letter of January 5, 2004, WD Energy listed the categories of documents it deemed to be privileged, including those it categorized as “settlement communications” and “voluntarily-created and produced material.” The Commission agreed, by letter of February 6, 2004, that WD Energy’s “requests for confidential treatment” under FOIA, contingent upon the requester’s right to appeal, “should be granted in full.”
While WD Energy was under investigation by the Commission, Gallo, a large California consumer of natural gas, sued WD Energy in the Eastern District of California on April 9, 2003. Gallo subsequently requested discovery of any documents in WD Energy’s possession that supported the factual findings in the Commission’s July 28, 2003 settlement order. WD Energy produced thousands of pages of documents and many hours of audio recordings in response to Gallo’s discovery requests; however, WD Energy resisted disclosing many of the documents it had provided to the Commission on the grounds of various privileges. WD Energy filed a lengthy privilege log, and, after briefing and argument, a Magistrate Judge resolved the discovery disputes.
The' Magistrate denied in part Gallo’s motion to compel production of documents that WD Energy had claimed were privileged, ruling that Fed. R. Evid. 501 provided a federal “settlement privilege” that protected documents created by WD Energy subsequent to the Commission’s investigation whose “tenor ... was to settle [the Commission’s] claims.” Order on Plaintiffs Further Discovery Motions (Docs.303-305, 306),
E. & J. Gallo Winery v. Encana Energy Servs., Inc.,
No. 03-5412, at 7 (E.D.Cal. Jan. 28, 2004) (“Magistrate’s ■ Order”). The Magistrate cited decisions in -the Eastern and Central districts of California and the Sixth Circuit’s decision in
Goodyear Tire & Rubber Co. v. Chiles Power Supply, Inc.,
Disclosure of the [Commission] documents would likely chill discussions and thwart tribunal efficiencies and public interests noted above. The [Commission] documents likely would be used to cross examine [WD Energy] under the ruse of impeachment evidence to eviscerate privacy expectations. [WD Energy has] produced documents provided to [the Commission] and existing prior to [the Commission’s] investigation. Moreover, the pending D.C. court action militates against overriding [WD Energy’s] assertion of the settlement privilege.
Magistrate’s Order at 7. Subsequently, the Magistrate stated in a letter of February 23, 2005, in response to Gallo’s letter requesting clarification, that he was not deferring to the D.C. district court but “[b]ased on WD Energy’s representations that it created and provided to [the Commission] certain documents to reach settlement,” he had “recognized and applied the settlement privilege to such documents.” On March 7, 2005, Gallo moved in the district court for reconsideration of the Magistrate’s Order, as clarified by his February 23, 2005 letter.
While this discovery dispute was being litigated in California, Gallo served on the Commission a third party judicial subpoena from the district court of the District of Columbia, directing the Commission to produce the documents it had received from WD Energy (and other energy companies) during its investigation of companies involved in the California natural gas market. Gallo filed a motion to compel the Commission’s compliance with the subpoena. WD Energy filed a response, arguing in part that “[m]any of the documents .that Gallo is seeking ... are documents that WD [Energy] prepared during the course of the [Commission’s investigation] and provided to the [Commission] in order to facilitate settlement.” WD Energy Services, Inc., Objections and Opposition to Subpoena Issued by E. & J. Gallo Winery to U.S. Commodity Futures Trading Commission of Dec. 16, 2004 at 10-11. The Commission responded that it would not assert any governmental privileges against compliance and would defer taking a position on the settlement privilege until WD Energy had identified the documents and transactions it considered protected by the settlement privilege. WD Energy subsequently filed an affidavit of counsel in support of its privilege claim, attaching the February 6, 2004 letter from the Commission.
The D.C. district court held a hearing on Gallo’s motion to compel on March 11, 2005. Both Gallo and the Commission challenged whether any of the documents sought under the subpoena would be covered by a settlement privilege. According to the Commission, no documents that remained subject to the-subpoena were created by WD Energy in order to settle the Commission’s enforcement action or as a result of settlement discussions, but were instead produced in response to the Commission’s investigatory demands. WD Energy responded that Gallo was collaterally-estopped by the Magistrate’s Order from enforcing its subpoena, and that the Commission had been made aware by WD Energy’s January 5, 2004 FOIA letter of the documents WD Energy claimed were privileged. Gallo also argued that the Magistrate’s Order was not a final order.
On April 28, 2005, the district court granted Gallo’s motion to compel, ruling that no estoppel attached to the Magistrate’s Order and that there was no federal settlement privilege under Fed. R. Evid. 501.
See Subpoena,
B.
Neither Gallo nor the Commission challenges WD Energy’s right to raise collateral estoppel as a ground to quash or modify a subpoena under Fed. R. Civ. P. 45(c)(3)(A)(iii). Although we have found no authority that authorizes a third party to a subpoena to advance an estoppel claim, this is a reasonable extension of the settled practice of allowing a party not named in a subpoena to challenge the subpoena in' ancillary proceedings' in the district court and on appeal under the
Perlman
doctrine.
See Perlman,
In rejecting WD Energy’s collateral estoppel argument, the district court focused on the fact that the Commission, as the holder of the documents and a participant in the settlement discussions underlying WD Energy’s settlement privilege claim, had a significant interest but, because it was not a party to the California proceedings, never had an opportunity to be heard on the settlement privilege issue.
See Subpoena,
First, it is unclear whether the same issues were presented in both the California and the District of Columbia proceedings. The question before the D.C. district court was the applicability of a settlement privilege to specific documents. WD Energy asserted the same settlement privilege in both fora, and Gallo’s California lawsuit is the underlying basis of WD Energy’s litigation in the D.C. district court. Nevertheless, it is not clear that the same documents are being contested here as in the Eastern District of California. The Magistrate’s Order specifies which documents were protected by the settlement privilege only by general reference to WD Energy’s privilege log and suggests that the Magistrate did not, in order to determine whether the privilege would apply to particular documents, personally examine the withheld documents or hear testimony about the circumstances surrounding their creation and use. The Magistrate’s Order refers only to the “tenor” of the documents based on WD Energy’s representations that the only withheld documents were both related to facilitating settlement with the Commission and created after the Commission “commenced its investigation.” Magistrate’s Order at 5.
Inasmuch as the Magistrate’s Order was designed to settle a large number of discovery disputes between the parties, and the Magistrate noted some deficiencies in WD Energy’s privilege log that made it difficult to determine in all instances which documents were claimed as privileged, it appears that the Magistrate contemplated the possibility of subsequent proceedings to define the circumstancés surrounding the creation of the documents and their role in the settlement discussions; then, either Gallo could contest the applicability of the settlement privilege on a document-by-document basis or the Magistrate could conduct an in camera review. So far as the record before this court indicates, this had not happened before the D.C. district court granted Gallo’s motion to compel the Commission to comply with Gallo’s subpoena. In any event, neither the D.C. district court nor the district court in the Eastern District of California appear to have examined the withheld documents or the privilege log. Thus, WD Energy has been unable to show that the specific documents Gallo seeks in the D.C. district court already have been determined to be privileged by the Magistrate.
This court is not in a position to determine with confidence that the withheld documents ruled by the Magistrate to be protected by a federal settlement privilege are the same documents WD Energy sought to have withheld, in the D.C. district court proceedings. The district court noted that before the Magistrate, WD Energy had asserted that the privilege applied to a larger set of documents.
See Subpoena,
‘ The uncertainty about the relationship between the documents in the two fora is highlighted by the Commission’s assertion in the D.C. district court that, upon reviewing the WD Energy documents in its possession, the Commission was' unclear whether any of the remaining subpoenaed documents would be covered by a settlement privilege. The Commission further observed that because no judicial officer had identified the withheld documents, were the D.C. district court to accord pre-clusive effect to the Magistrate’s Order, the Commission might have to go to California in order to determine which documents were covered by the settlement privilege. By failing to timely make a record in the D.C. district court that unambiguously indicated that the same “settlement” documents were at issue in both fora, WD Energy failed to meet its burden to show that the same issue was presented in the California proceedings.
Second, there is a potential ambiguity in the Magistrate’s- Order about whether the question of privilege was actually and necessarily determined.
See NextWave Pers. Commc’ns, Inc. v. FCC,
The Supreme Court has observed: “Re-determination of issues is warranted if
*749
there is reason to doubt the quality, extensiveness, or fairness of procedures followed in prior litigation.”
Kremer v. Chem. Constr. Corp.,
Therefore, we hold that the district court did not err in refusing to give preclu-sive effect to the Magistrate’s ruling on the settlement privilege.
III.
WD Energy also contends that the doctrine of law of the case called for deferring to the Magistrate’s determination that the withheld documents were protected by a federal settlement privilege “in these coordinated proceedings” to compel the Commission to produce the same documents. Its contention is meritless. Law of the case doctrine applies within the same case, proceeding, or action.
See generally Crocker v. Piedmont Aviation, Inc.,
IV.
Fed. R. Evid. 501 provides, in relevant part:
the privilege of a witness, person, government, State, or political subdivision thereof shall be governed by the principles of the common law as they may be interpreted by the courts of the United States in the light of reason and experience.
The rule’s invocation of “reason and experience” was drawn from
Wolfle v. United States,
The general mandate of [Fed. R. Evid. 501] was substituted by the Congress for a set of privilege rules drafted by the Judicial Conference Advisory Committee on Rules of Evidence and approved by the Judicial Conference of the United States and by this Court. That proposal defined nine specific privileges, including a husband-wife privilege ... and eliminated the privilege for confidential marital communications. In rejecting the proposed Rules and enacting [Fed. R. Evid. 501], Congress manifested an affirmative intention not to freeze the law of privilege. Its purpose rather was to ‘provide the courts with the flexibility to develop rules of privilege on a case-by-case basis,’ 120 Cong. Rec. 40891 (1974) (statement of Rep. Hungate), and to leave the door open to change.
Id.
at 47-48,
It is to the federal courts’ authority under Fed. R. Evid. 501 that WD Energy looks for the establishment of a federal settlement privilege to cover the documents it claims were prepared for the purposes of facilitating settlement of a pending enforcement action brought by the Commission. WD Energy contends that the district court, by failing to recognize that the Sixth Circuit’s decision in
Goodyear Tire & Rubber,
This case does not present the occasion to examine whether federal common law provides a settlement privilege. It is well established that the proponent of a privilege bears the burden of demonstrating facts sufficient to establish the privilege’s applicability.
See, e.g., United States v. Legal Servs. for N.Y. City,
Although Federal Rule of Civil Procedure 45(d)(2) does not speak directly to the burden on third parties raising claims of privilege under the
Perlman
doctrine, the applicabihty of a similar burden is natural. Rule 45(d)(2) is generally satisfied by the submission of a privilege log detailing each document withheld and the reason.
See Tuite,
In light of the admonitions from the Supreme Court and this court that courts proceed cautiously in deciding whether novel privileges exist under federal common law,
see Univ. of Penn. v. EEOC,
The district court asked the pertinent questions during the March 11, 2005 hearing on Gallo’s motion to compel but re *752 ceived only incomplete responses. First, the district court sought to clarify which documents were at issue. Gallo and the Commission, after reviewing the WD Energy documents in its possession, had asserted in their pleadings that WD Energy had failed to carry its burden of building a record that could demonstrate that any of the subpoenaed documents were privileged. At the hearing Gallo argued that “it was incumbent upon WD [Energy] ... to specifically tell this [cjourt with a great deal of accuracy” which subpoenaed documents were claimed as privileged. Transcript of March 11, 2005 at 7-8. When the district court expressed concern that the Commission may possess documents very clearly in the nature of settlement proposals, Gallo responded, “If there are, WD [Energy] hasn’t told us what they are, and it was their duty to do so .... ” Id. at 10.
WD Energy, for its part, conceded that it bore the burden of providing a “very specific description” of the documents it claimed were privileged: “it’s clearly necessary for us to do that.” Id. at 59-60. At the hearing, WD Energy told the district court that in responding to the FOIA requests following its settlement with the Commission, it had “advised the [Commission] of exactly the documents that [WD Energy] sought to protect because they were created and provided to the [Commission] for the purpose of facilitating a settlement ....” Id. at 58. The affidavit of its counsel had declared that “certain of these materials were prepared for the sole purpose of facilitating and furthering settlement with the [Commission],” that “[a]ll of these materials were voluntarily provided to the [Commission] and [that] they were provided with an expectation that the information would remain confidential and would not be used against WD [Energy] in subsequent litigation .... ” Affidavit of Douglas F. John of Feb. 25, 2005 at -2. Attached to the affidavit was a copy of the Commission’s February 6, 2004 letter stating that WD Energy’s request for confidential treatment-of its submitted documents under FOIA “should be granted in full.” The district court noted that various other affidavits submitted by WD Energy “discuss in general the kinds of documents and in general the kinds of harm.” Transcript of March 11, 2005 at 20. At the hearing, WD Energy also produced, for the first time in the D.C. district court proceeding, an excerpt from its January 5, 2004 FOIA letter to support its assertion of confidential treatment. Id. at 60. This one-page excerpt contained WD Energy’s listing of sets of documents it claimed (and the Commission had agreed) merited confidential treatment under FOIA. Absent evidence of the circumstances surrounding the creation of the documents and their role in settlement discussions, however, identification of the documents was an incomplete response to the district court’s inquiry.
Second, the district court asked why WD Energy had previously provided only generalized descriptions of these documents. WD Energy explained its refusal to “publicly disclose” this list or to provide a “very specific description of what we had provided or created for the [Commission],” id. at 59, on the ground that a more specific assertion would have vitiated the privilege, see id. WD Energy explained that its business records were already in Gallo’s possession while the contested documents were created to help the Commission understand those business records. If this were the case, then it behooved WD Energy to proffer the documents or a specific description of them in a privilege log for in camera inspection by the court.
Third, the district court sought an explanation of how it should relate the categories of documents identified in the excerpt of the January 5, 2004 FOIA letter *753 to the timeline of the Commission investigation. According to Gallo, WD Energy had not shown -there was a mutual understanding between WD Energy and the Commission that the documents would be produced to settle a potential claim in a civil action; rather, Gallo asserted, WD Energy was relying upon its “supposed subjective intent at the time [it] provided [documents] rather than on facts demonstrating that [there] were, in fact, settlement discussions going on and [that] specific documents ... were created pursuant to settlement discussions.” Id. at 14-15. The district court noted, based on the Commission’s position that prior to July 2003 it was prepared to move forward with an enforcement action, that seven of the sets of documents listed on the excerpt from the 2004 FOIA letter appeared to predate July 2003. (The only remaining subpoenaed set of listed documents was dated July 11, 2003.) “How,” asked the district court, “am I ... to ascertain whether something created on March 7, 2003, which is a series of spreadsheets^] is actually a settlement document as opposed to just some information that is being submitted to the investigating agency in an attempt either to cooperate in the investigation or to talk the agency out of taking any enforcement action?” Id. at 62. WD Energy responded that these documents were distinguished from the many other documents WD Energy had provided to the Commission because they did not exist on January 24, 2003, when WD Energy had received the Commission’s subpoena, “were all stamped privileged and confidential,” id. at 64, and “belie the efforts of somebody intending to litigate a case * * * [because] they were ■ concessions. They were quid pro quo,” id. Even so, in order to respond to the district court’s inquiry, WD Energy needed to identify the type of information that would appear on the March 7, 2003 spreadsheets that would indicate that WD Energy submitted these documents to the Commission to facilitate settlement. Again, WD Energy needed to provide the district court with detailed information about the role of the documents in particular settlement discussions.
Only'WD Energy’s proffer of the excerpt of the 2004 FOIA letter even arguably answered the district court’s questions about which documents WD Energy claimed would be protected by a federal settlement privilege. The Commission argued that this proffer was “too little, too late.”- Id. at 144. Even with the excerpt, the-district court was unaware of the specific connection between the listed documents and the Commission’s investigation, which was the basis for claiming a settlement privilege. Although the district court, after examining the excerpt, better understood in what respect WD Energy had been claiming a privilege over only a “small group” of documents, the eleventh hour .proffer deprived the district court of responsive pleadings by Gallo and the Commission, which could have shed additional light on whether these documents had been prepared for use in settlement discussions or in response to the administrative subpoena and other Commission requests before any settlement discussions began. Further, while WD Energy’s argument that the listed documents could be distinguished from others it had provided the Commission because they were concessions, WD Energy did not explain away the Commission’s contrary view of events prior to July 2003.
Moreover, by its own terms, WD Energy’s January 5, 2004 FOIA letter did not address privileges under the federal rules but confidentiality for purposes of FOIA. The Commission’s acceptance of WD Energy’s confidentiality claims did not confer upon these documents a privilege from
*754
discovery. FOIA’s exceptions to - disclosure limit only the right to information conveyed pursuant to that statute,
see
5 U.S.C. § 552(d), and other limitations on the Commission’s authority to .publish information, such as 7 U.S.C. § 12(a)(1), do not alter the Commission’s duty to comply with lawful subpoenas after notice to the party whose information is sought,
see id.
§ 12(f);
Friedman,
Unlike the district court in
Goodyear Tire & Rubber,
WD Energy did not file a privilege log here, and thus the record before the D.C. district court consisted of WD Energy’s general characterizations of the disputed documents and settlement discussions, a belated description of the specific sets of documents, and contentions by Gallo and the Commission that the documents generally and specifically described by WD Energy would not be covered by a settlement privilege. There were no factual findings regarding settlement discussions made in the proceedings in the Eastern District of California that could fill these gaps and potentially lessen WD Energy’s burden in the D.C. district court. Without such information, the district court lacked a sufficient factual context within which to evaluate whether withholding the listed eight sets of documents advanced important public interests, satisfied the justified ex-portations of the parties, or would have been treated as privileged under various State laws — each of which can be an important consideration under
Jaffee
and other relevant caselaw.
See, e.g., In re Sealed Case,
Accordingly, we affirm the discovery order granting Gallo’s motion to compel production by the Commission. The Magistrate’s Order was not entitled to preclusive effect under the principle of collateral es-toppel, and the law of the case contention lacks merit. We do not address the merits of . WD Energy’s settlement privilege claim; rather, we affirm on the alternative ground,
see Nat’l Ass’n of Home Builders v. U.S. Army Corps of Eng’rs,
