See, fatty cop didn't care about Niko stabbing his partner or shooting all of those people...but once that East Europe-y bastard sort of shouldered him, all bets were off.
You can tell from his eyes.. he is dead to the rest of the world. Once he realized his wife was cheating on him and his daughter was turning tricks, he walled off his emotions just to maintain the tenuous grip on the small amount of sanity that was left to him.
This shit makes Scorsese look like he directs the elementary school christmas plays. I laughed, I cried; I yelled at my screen in rage in the last few moments.