Oh, I definitely think Jensen was right. I'd be inclined to make the argument that since Jensen has been the embodiment of Dean for four years (at that point in time), and he's been giving the character life, that Jensen, at this point, actually understands the character better than Kripke does.

However, Jensen is a professional, and though he expresses his views on what works and what doesn't, I wouldn't expect him to contradict his director.