"Yeah. They should know that it might not feel good, but sometimes you don't have much of a choice, though."

And then there are times when that explanation doesn't work--at least with himself. Though in that case it's not killing an animal. It's the times he's had to kill someone he knows to prevent a larger disaster, and for a moment he can see the look on Curtis' face again, as he realized that Jack had shot him and he was bleeding out.