Minton v. Gunn, 355 S.W.3d 634

Minton developed TEXCEN and leased it to Stark; he did not disclose to Stark his intent to lease TEXCEN for experimental purposes.
Minton obtained the '643 patent in January 2000 for an interactive securities trading system similar to TEXCEN.
Minton sued NASD/NASDAQ in federal court for patent infringement; district court found the '643 patent invalid under the on-sale bar.
Minton attempted to rely on the experimental use exception to save the patent from invalidation; the court denied relief on reconsideration.
Minton’s state-based legal malpractice suit was filed against his original patent litigators for failing to timely raise the experimental use exception.
The Texas appellate court held that it lacked subject-matter jurisdiction; the supreme issue was whether exclusive federal patent jurisdiction applied.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Grable-based embedded patent issues trigger exclusive jurisdiction	Minton relies on Air Measurement and Immunocept to show jurisdiction.	Gunn contends Grable analysis does not support exclusive jurisdiction here.	Yes; four Grable elements satisfied.
Whether experimental use exception is a necessary element	The exception is essential to prove avoidance of the on-sale bar.	The issue is not necessary given facts show primarily commercial purpose.	Yes; the exception is a necessary element of the malpractice claim.
Whether the experimental use issue is actually disputed	There is a dispute over whether TEXCEN lease was experimental.	Gunn argues no viable experimental-use defense existed.	Yes; the viability of the exception is contested.
Whether the experimental use issue is substantial	Resolution of the patent issue would determine the malpractice claim.	Issue is fact-bound and limited to this case.	Yes; it is a substantial federal question.
Whether adjudicating this federal issue in federal court would upset the federal-state balance	Uniform patent law and federal forum benefit the enforcement of patent rights.	State regulation of legal malpractice should remain in state courts.	No; exclusive federal jurisdiction is justified for this case, given Grable framework.

Grable & Sons Metal Prods. v. Dane Eng’g & Mfg., 545 U.S. 308 (U.S. 2005) (four-factor test for embedded federal questions)
Christianson v. Colt Indus. Operating Corp., 486 U.S. 800 (U.S. 1988) (arising under patent law requires substantial federal question)
Air Measurement Technologies, Inc. v. Akin Gump Strauss Hauer & Feld, L.L.P., 504 F.3d 1262 (Fed. Cir. 2007) (embedded patent issue can confer exclusive jurisdiction)
Immunocept, LLC v. Fulbright & Jaworski, LLP, 504 F.3d 1281 (Fed. Cir. 2007) (patent claim scope as a substantial federal issue in malpractice suit)
Empire Healthchoice Assurance, Inc. v. McVeigh, 547 U.S. 677 (U.S. 2006) (limits on what constitutes a substantial federal issue)
Singh v. Duane Morris LLP, 538 F.3d 334 (5th Cir. 2008) (federalism considerations in embedded patent-law malpractice cases)
USPPS, Ltd. v. Avery Dennison Corp., 647 F.3d 274 (5th Cir. 2011) (application of Air Measurement/Immunocept reasoning in patent-related claims)
Davis v. Brouse McDowell, L.P.A., 596 F.3d 1355 (Fed. Cir. 2010) (patent-related malpractice can be substantial depending on underlying issues)
Warrior Sports, Inc. v. Dickinson Wright, P.L.L.C., 631 F.3d 1367 (Fed. Cir. 2011) (malpractice cases tied to patent infringement merits may raise substantial issues)
U.S. Valves, Inc. v. Dray, 212 F.3d 1368 (Fed. Cir. 2000) (patent issue construction can be central to state-law claims)