Nawzuddin Siddiqui stated in an interview that he did this film to uplift his market value so that his small films will do better. He got praised too for his acting.
In the last scene when Devi Lal emerges as a Police Officer, just a day before he was robbing and a day later he is a Cop. If he was a cop earlier, surely Himansu would have known about it.
Himanshu does not arrest Devil when he throws a loser party. Though Himanshu knows that Devi Lal Singh is the Devil, responsible for damaging property in the bus chase scene as well as causing the death of at least 1 or possibly 2 policemen who were flying the chopper. In fact, Himanshu gives the Devil an opportunity to rob again on November 14th.