McWilliams v. Board of County Commissioners, 268 P.3d 79

McWilliams was injured July 26, 2008 on a county-line road between Comanche and Caddo Counties, with the accident in Caddo County.
McWilliams timely notified Comanche County of the tort claim via email on November 4, 2008; Comanche asked for a more descriptive location on November 10, and McWilliams complied.
Unbeknownst to McWilliams, Comanche and Caddo Counties had an undisclosed oral agreement over maintenance of the county-line road for more than twenty years, designating Caddo for the segment where the accident occurred.
Comanche County repaired the road immediately after notice and was later followed by a full overlay by Caddo County, with no disclosure of the oral agreement to McWilliams.
McWilliams filed suit in August 2004; Comanche County answered saying it lacked sufficient information; mediation failed; Comanche filed a combined Motion to Dismiss/Summary Judgment in November 2005, asserting liability based on the oral agreement.
On remand, a one-day non-jury trial led to a finding that Comanche County was not liable; the Court of Civil Appeals affirmed; the Supreme Court reversed, held estoppel applies, and remanded for proceedings consistent with the opinion.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Comanche County is equitably estopped from denying liability	McWilliams argues concealment of the oral agreement and dilatory conduct harmed him, justifying estoppel against Comanche.	Comanche maintains no duty or liability due to lack of notice and to the undisclosed agreement, and seeks dismissal.	Yes; County estopped from denying liability.
Whether the undisclosed oral agreement binds the parties and tolls liability	McWilliams seeks to bind both counties due to the ongoing undisclosed agreement and shared maintenance duties.	Comanche argues the oral agreement cannot bind non-contracting parties and was not discoverable by McWilliams.	Yes; the oral agreement may bind and create liability against Comanche (and potentially Caddo).
Whether § 2015(C) relation back allows adding Caddo County as a party	Addition of Caddo arises from the same occurrence and relates back to the original filing date; no prejudice to Caddo.	Comanche asserts improper party substitution or prejudice if Caddo is added after limitations.	Yes; relation back permitted.
Whether GTCA notice and procedural requirements bar the claim	Plaintiff complied with timely notice; GTCA should not bar where equity demands substitution and relief.	Defendant argues GTCA notices and deadlines govern, potentially barring relief.	Not determinative; relation back and estoppel supersede rigid GTCA timing in light of equity.

Pan v. Bane, 141 P.3d 555 (2006 OK 57) (relation back under § 2015(C) permits adding parties related to same occurrence)
Hathaway v. State ex rel. Med. Research & Technical Auth., 49 P.3d 740 (2002 OK 53) (GTCA purpose emphasizes notice and reasoned equity over hyper-technical application)
Sullivan v. Buckhorn Ranch P'ship, 119 P.3d 192 (2005 OK 41) (elements of equitable estoppel and concealment may support estoppel against public entities)
Krupski v. Costa Crociere, 130 S. Ct. 2485 (2010) (relation back and misidentification issues under Rule 15(c))
Calvert v. Tulsa Pub. Schs., Indep. Sch. Dist. No. 1, 932 P.2d 1087 (1996 OK 106) (governmental tort claims; context for governmental liability and notice)
Green Bay Packaging v. Preferred Packaging, 932 P.2d 1099 (1996 OK 121) (cited regarding related principles in maintenance of governmental obligations)
Hawk Wing v. Lorton, 261 P.3d 1122 (2011 OK 42) (noting limits on limitations defenses in the GTCA context)
Merritt v. Merritt, 73 P.3d 878 (2008 OK 68) (equitable principles and weight of the evidence in GTCA-related matters)