But anyway I decided to read all of the replies because of that red portion, and well yeah I think some people just got the wrong idea that's all! So just like Madhavan's character Farhan in 3 Idiots kept saying: "Ignore kar, ignore kar!!" (:
But coming to your actual post, I kind of agree. I mean I think Zoya's immediate reaction was totally justified, and Asad badly needed that talking down to. But after it all sinks in, shouldn't Zoya recall that face-off with Tanveer (like you said as well) and then maybe try to put two and two together? Her shocked emotional state didn't allow Asad to defend himself, but he did manage to say "mujhe kuch yaad nahi aata" and "tum bhi thi wahan" in a confused and dazed manner, so after calming down, maybe Zoya should try to piece the puzzle together.
But according to what we know, Zoya still jumps to the conclusion that Asad still knowingly betrayed her, and she runs off to Ajmer. So it means even after calming down a little, she still didn't try to figure it out. I mean Tanveer even called her up herself to tell Zoya to come to that deserted place, that in itself is clue enough that she probably planned the whole thing.
Hope they prove us wrong and do show Zoya putting her thinking caps on. We all have seen enough of Asad not using his brain when it comes to his Tanu, we don't need to see the same with Zoya haha, at least she should be a little smarter right!