I think the way he treats her like that is because she means so much to him...she affects him the most..he loves her but can't tell her...and he beleives that she lvoes someone else...thus his rough behaviour....
I am not saying its right...but then...whe one is angry..has lost control of one senses...its not odd either is it.....
I agree with you completely krishna.. Prachi affects him the most.. Even though he is angry with Prachi, he still has some faith left in her.. I think the mandir scsne was the last straw for him.. whatever faith or trust that Milind had for Prachi shattered when he beleived Prachi married SaSu. thus his hearbreak coupled with anger made him behave in such extremes with Prachi.
I will never say it is the right way to behave to your wife when you are angry... but we have to notice more than Sukriti's betrayal it was Prachi's so called betrayal he was more affected about.. thus such rough behaviour..