With due respect, Dev is not comparable to Nitya.
Dev has seen more of the world than Nitya. More educated and more acquainted with real world outside.
Dev has many more resources than Nitya ever had.
Dev is a man. Men do not have limitations that women have.
Dev is not the one who was affected. Nitya was in panic as it was her sister who was victim and partly in guilt over her mistake. Being third party observer and being firsthand observer of actual happenings are different things. Dev does not have the baggage that weighed Nitya down.
Hence the impulsive, ignorant and full of mistakes behaviour cannot be overlooked. Or rationalised, at least in my eyes.
He has to travel that trail but as a more logical observer than a victim himself.
I expect different story when watching a show than same old background seeped in history, mythology or even yesteryear films.
As Debs pointed out, Dev has made glaring errors and oversight. Why would Durga show this concern for just another patient? Why would she marry just for getting justice for Payal? Why Goenkas get this worked up at mention of Mitras and rape case? Why he got attacked twice after Shaurya threatened him? How did Durga reach Mitra house on wedding night? Hpw did she know Dev must have come here? These are just few of the many questions he never ponders on.
Forget reaching a conclusion. Dev has never even thought about these things!