In what circumstances will a jury acquit a defendant who was charged with a burglary but the evidence presented to the jury was ambiguous and ambiguous?

In People v. Failla, supra, 64 Cal.2d 560, 51 Cal.Rptr. 103, 414 P.2d 39, the defendant was charged with burglary, but "the evidence presented" was ambiguous and "subject to [the] [14 Cal.4th 287] inference not only that defendant intended to commit one or more felonies ..., but also intended to commit one or more misdemeanors ... or acts which are not crimes" (id., at p. 565, 51 Cal.Rptr. 103, 414 P.2d 39), in which event the jury was bound to acquit. In these circumstances, this court concluded the definition of "felony" was " 'closely and openly connected with the facts of the case' " and should have been given sua sponte by the trial court. (Ibid.) The duty arose, however, only upon evidence permitting a factual finding favorable to the defendant. (Id., at p. 564, 51 Cal.Rptr. 103, 414 P.2d 39.)