I voted Yes but I would take some abilities away.. like immune to disease. Then I'd let him catch one or two. It might change his ways.
But in all seriousness I do think that if a player can keep up a LG image and Role play him properly I dont see why not. I have a barb who is actually a pal...
I play a barb that had his pockets picked by another party member.
I caught him once and cut off his hand in one movement.... soon after that he left the party.
I think my barb was being merciful