On the surface, the war waged by Mac's Local Eats earlier this week was a Facebook battle — a fight between people who'd never dined at the Dogtown restaurant (armed with one-star reviews) and its friends and fans in the community (who responded with five-star ones). But underneath all the passive-aggressive liking and sad reacts, the disagreement was about a fundamental difference in belief: Is there a humane way to kill an animal?If you ask chef Chris McKenzie, the answer is yes.…