I suppose if all your proofs work out, that's fine. However, if this is for a test or exam, it's best to memorize the proof you were taught, as that's what your professor will deem correct, even if it's actually wrong it's what they will think is right.
I really can't say, because I've only ever been shown one proof for each theorem. Sorry if that wasn't helpful, I just thought I'd throw it in there. :)