Right. I think this is the promise of Java generics: we promise we'll warn you if you're relying on dynamic type checking because we can't prove all dynamic type checks will pass.

This article gives a series of examples that break that promise.

In some situations. The examples in this article, I think, make it clear that for a lot of "broken code" these errors are caught. It's too bad that there are edge cases, but that is Java all over, in my opinion.