The Theory of Trial Principle

Navarrete v. Meyer, No. D067454 (D4d1, as modified Jul. 22, 2015)

When you try and lose a case based on a core theory that applies the facts to the law, an appellate court generally won’t let you change that theory in seeking reversal. This is known as the “theory of trial principle.” But the principle isn’t super-rigid. So if your appeal is generally consistent with your trial theory but invokes more detailed, while consistent, legal analysis, the theory doesn’t preclude a reversal. After all, sometimes things are just a little more thoughtful given the pace and focus of an appeal. The appellate lawyers in this case invoked a statute that hadn’t been addressed in the trial court briefing. But their theory was more or less consistent, so the theory of trial principle wasn’t offended, and they could make their argument on appeal.

That being the case, and the argument being permitted, the trial court erred in granting summary judgment.
 
Reversed.