What rights does a defendant have to a judge to instruct the jury on his defense?

In general, "[a] defendant is entitled to have the judge instruct the jury on his theory of defense, provided that it is supported by law and has some foundation in the evidence." United States v. Mason, 902 F.2d 1434, 1438 (9th Cir.1990). Logically, if the parties dispute whether the required factual foundation exists, the court should apply an abuse of discretion standard of review. In this case, the ultimate issue is whether "other instructions, in their entirety, adequately cover that defense theory." Id. This is a question of law and, as in Mason, should be reviewed de novo. See id. There is no conflict; the question turns on the issue for review.