
You'll notice that Asad's sherwani is unbuttoned, much like a month ago when he woke up next to Tanveer and then ran after Zoya with an unbuttoned sherwani.
So here's my two cents: This whole thing is ALL Zoya's plan.
During the Tanveer-Zoya confrontation, Zoya says this:
Tumne apni chaal chali aur tumne samjha tum jeet gayi? Ab meri baari hai Tanveer. Pehla waar tumhara tha, akhri waar main karoongi.
I think Zoya realized that just going up to Asad and telling him directly that Tanveer's evil and she planned the whole thing is not going to work, because he's not going to buy it immediately, considering the fact that he trusts Tanveer as much as he does (Why he does, please don't ask me, it's beyond me hahaha).
So she came up with an elaborate plan for Asad to relive the night, but with a twist, where when he wakes up, he realizes that Tanveer tricked him. I don't know exactly how it's going to play out, but that's just what I think is happening (: