YES! I was yelling at Heath to shoot David.
Yeah, the group was a bunch of aholes there. Heath could have shot him. Michonne could have stabbed/slashed his head through the fence. Nope, just walk away and let the poor dude end his life as a walker snack feeling every last set of teeth. I can suspend disbelief on a lot of stuff, but this little thing bothers me on a writing level.