Monroe Guaranty Insurance Company, a Member of the Fcci Insurance Group v. Bitco General Insurance Corporation, Formerly Known as Bituminous Casualty Corporation, 640 S.W.3d 195

5D Drilling & Pump Service performed drilling for Jones (J & B Farms) in summer 2014; Jones sued 5D in 2016 for negligence and breach of contract alleging drilling damaged his property but the petition omitted dates for when damage occurred.
BITCO insured 5D from Oct 2013–Oct 2015 and defended the suit under reservation; Monroe insured 5D from Oct 2015–Oct 2016 and refused to defend, asserting the alleged property damage occurred before its policy and was thus excluded by a prior-knowledge clause.
BITCO sued Monroe in federal court for declaratory relief/contribution of defense costs; the parties stipulated the drill bit became stuck in or around November 2014 (during BITCO’s policy period).
The federal district court applied the eight‑corners rule, refused to consider the stipulation, and held Monroe had a duty to defend; Monroe appealed.
The Fifth Circuit certified two questions to the Texas Supreme Court: (1) whether the Northfield exception to the eight‑corners rule is permissible under Texas law; and (2) whether courts may consider extrinsic evidence of the date of an occurrence under that exception.

Issue	Plaintiff's Argument (BITCO)	Defendant's Argument (Monroe)	Held
Whether Texas permits an exception to the eight‑corners rule (Northfield) allowing extrinsic evidence when pleadings are silent on a coverage‑determinative fact	Eight‑corners should control; extrinsic evidence generally not allowed except very narrowly (to avoid undermining insured’s defense)	Texas should adopt Northfield‑style exception so extrinsic evidence can be used to resolve coverage gaps	Yes. Texas permits consideration of extrinsic evidence when (1) it goes solely to coverage and does not overlap merits, (2) it does not contradict pleading allegations, and (3) it conclusively establishes the coverage fact.
Whether extrinsic evidence of the date of an occurrence may be considered and whether the parties’ stipulation (Nov 2014) is admissible here	Date evidence overlaps with liability merits in continuing‑damage claims and thus cannot be used to defeat duty to defend	Date evidence is a proper coverage fact; the stipulation conclusively shows damage predated Monroe’s policy so no duty to defend	Date evidence may be considered in principle under the adopted standard, but the Nov. 2014 stipulation cannot be considered here because using it would overlap with the merits of liability.

Northfield Ins. Co. v. Loving Home Care, Inc., 363 F.3d 523 (5th Cir.) (articulated the federal “Northfield” exception to the eight‑corners rule)
Heyden Newport Chem. Corp. v. S. Gen. Ins. Co., 387 S.W.2d 22 (Tex.) (adopted the eight‑corners rule in Texas)
GuideOne Elite Ins. Co. v. Fielder Rd. Baptist Church, 197 S.W.3d 305 (Tex. 2006) (refused extrinsic evidence that contradicted pleadings)
Loya Ins. Co. v. Avalos, 610 S.W.3d 878 (Tex. 2020) (recognized limited exception for collusive/fraudulent pleadings)
Richards v. State Farm Lloyds, 597 S.W.3d 492 (Tex. 2020) (explained eight‑corners as enforcing the parties’ written agreement)