Of course, he can exercise that right "badly" if he chooses to do so. Perhaps it was an inadvertent mistake, a hip-shot slip of the tongue. I sure hope so.
It's just that spokesmen for any cause are far more effective when they speak and write articulately - and when it's a cause I believe in personally, I want them to be as articulate and effective as possible. Can you imagine Patrick Henry making such a statement ??
Thor's gaffe is more than a 'grammatical imperfection,' it is a complete malaprop a la Yogi Berra.
Lighten up - where's your sense of humor ??