I hope this is the last time I see "the exception that proves the rule" in the context of programming languages. It's a wart. You know what would better prove the rule? No exceptional cases at all.
Yes! Absolutely. The phrase "the exception proves the rule" is a tired, worn out, clichéd contradiction in terms that must have meant something at one time I'm sure but can only be superfluous in most cases now.
I think I've heard it used reasonably, but I can't really remember the specifics. Basically, it's when the cause for the exception follows naturally from the logic behind the rule. Contrived example: If something holds for most birds, an exception for penguins might qualify.
In any case, this is just an exception that breaks the rule.