How have the courts interpreted contingent intent in the context of a burglary case?

In his opening statement, defense counsel argued appellant did not burglarize the fire station because there was no evidence he "was doing anything other than trying to leave" the station. In response and relying on People v. Fond (1999) 71 Cal.App.4th 127 the prosecutor requested a special jury instruction on contingent intent for purposes of burglary. The instruction provided, "It is not a defense to the crime of burglary that, prior to entry, the intent to commit a theft or some other felony is a contingent one. If you find the evidence proves that, prior to entry, the defendant harbored an intent to commit a theft or some other felony depending on opportunity or circumstance, then the intent element may be satisfied." Defense counsel objected that the proposed instruction violated appellant's due process rights and claimed the instruction weakened the element of intent required to support a burglary conviction.