I don't understand the benefit of rushing to the principal, he's not running away... you're not trying to get even with the rebbe, you're trying to help the situation. By circumventing the rebbe you may may be getting yourself into a messy situation for the year...
I hear you. But if the Rebbeim, or at least this Rebbe, speaks like this there's a good chance that its:
a) school policy to talk like this (or at least they are ok with it) or
b) the Rebbe (really believes this and) talks like this when its against school policy
Either way, there's not really such a reason to go to the Rebbe first.
What about what Avromie7 wrote, "Alternatively, ask the principal for advice. You can make it clear that you're not necessarily asking for him to get involved."?