To be short (and sorry i'm so late with replies) Jensne did speak in past tense but he could tell openly only about eps we already saw to not reveal any spoilers and that interview was about them filming 8th ep so that's why the general impression was that he was negative about the way they wrote Dean not only for first ep but for more eps and he didn't use present tense because maybe just now the things got better.
I trust Jensen too it's just sad that he must work for all of them to *rix* things on the show.