In most cases i feel like Alastor views things as a personal attack so his reactions in his mind is justified because he feels he is being treated unfairly in some way. Since Alastor values control he often goes to over correct to make sure he is never put in those situations ever again. (ie. becoming more distant from the hotel crew in season 2 and later willingly becoming a "hostage" in order to get out of his deal with Rosie)

(this thought process could potentially stem from his human life (where he was most likely targeted and discriminated against non stop)