What is the test for transferred intent in the doctrine of self-defense?

"[T]he reasoning [of transferred intent] applies equally to carry the lack of criminal intent to the unintended consequences and thus preclude criminal responsibility." (People v. Mathews (1979) 91 Cal.App.3d 1018, 1023 (Mathews), first italics in original, second italics added.) Accordingly, "the doctrine of self-defense is available to insulate one from criminal responsibility where his act, justifiably in self-defense, inadvertently results in the injury of an innocent bystander." (Id. at p. 1024, italics added.)