the thing is CMN, that any misery is up to you
you have the choice on whether to react that way, or take the high road and not be bothered by some twat. Why on earth would he have enough importance to make you affected by his views!?
as for the dog killer, he was an extremely nasty person and he killed the dogs you loved. Losing the dogs was enough to make you miserable, agreed, but the guy just needed his head examining.