Let's compare the two situations:
Lewis is partying with his boys at the Super Bowl. They're walking down the street and words are exchanged with another group of men. A fight ensues. I don't know about you but I've always thought the objective of a fight was to hit the other guy often/hard enough so he couldn't or didn't want to hit you anymore.
Vick runs a dogfighting ring for years with his boys. He has some dogs that he no longer wants. Since they're not the sort you can adopt out or take to the vet for a humane injection, he has to put them down himself. He could inject them or put a single bullet in their brain. However, he decides electrocution, drowning, slamming to the ground, hanging and whatever else was a much better option. For years. Not one fleeting moment. Years.
Seriously, who's the bigger scumbag?