No, he doesn't know that, because he gets his own kick when he pulls the trigger and he knows - oh, he knows - it is an itch, not a last resort, not a circumstance that drives a man to excessive violence. He has long ago stopped trying to explain away the blood on his own hands. And while he has had a chance to start over, more than a century later in a place that has completely changed with people who don't know him, he knows better. One cannot simply choose to walk away from being 'that guy' at one's own convenience. The suffering has already been inflicted. The sins committed. Doc is 'that guy' as much as Negan is.

He has been trying to change, to reconcile 'that guy' with 'this guy', which is the only reason he tosses the fragile papers aside and starts walking out of the room. If he stayed and listened to more bullshit he might have felt like throwing a punch. But throwing a punch does not a better man make, as satisfying as it would have felt.

For someone who takes it outside at high noon knowing his winning streak would never be beat, it's so hard to walk away. But he's getting better at doing it.