Cornet v. State
In Cornet v. State, 417 S.W.3d 446, 451 (Tex. Crim. App. 2013), a case involving the omission of a medical-care defensive instruction, the Court of Criminal Appeals held the omission was harmless error. 417 S.W.3d at 453.
It observed that the omission of an instruction on a confession-and-avoidance defense "is generally harmful because its omission leaves the jury without a vehicle by which to acquit a defendant who has admitted to all the elements of the offense." Id. at 451.
Nevertheless, the court conducted a record-specific analysis of harm and held that the jury implicitly rejected the defendant's defense when it convicted him of a second offense involving the same event that was inconsistent with his claim of providing medical care. Id. at 452.