I think he did the right thing, even though I feel bad for Melissa
I agree. Even though I knew what was coming, it was hard watching that part. I really think he should have been honest with her and just said, I made mistake, I'm really in love with Molly, rather than going on and on about the "chemistry" changing.
I don't believe in all the "planned" crap Reality Steve is trying to sell

, but I wasn't surprised that Jason changed his mind. I thought all season long that he was incredibly wishy-washy and couldn't make a decision to save his life, turns out I was right.

I blame DeAnna though and her whole, "I picked the wild card" comment. Jason's whole faced just dropped when she said that and while it shouldn't have changed his mind, he was so conflicted at that point that I think it might have made a difference, especially since he'd been on the receiving end of her decision.
I think his gut was telling him to pick Molly but his brain was saying that Melissa was who fit his "idea" of the type of girl he wanted. If he'd just listened to Trista, he would know that the reason that worked out was because she picked the guy totally different from anyone else she ever dated.
