As to my tone, I am neither angry not vindictive at all
Ummmm....I think most people would agree that saying you "NUKED" him is pretty aggressive. (Do you make a habit of not owning your angry feelings?)
As for whether he'll come after you - you just ruined his job, plan to ruin his relationship, and somehow you don't think this crazy irrational guy is gonna come after you? I would be VERY afraid and VERY careful. VERY. SERIOUSLY.
(Note: I think it was appropriate to warn his work, and given OW's precarious mental health and your previous contact with her parents, it may be appropriate to warn them also - but you have to rein in that part of you that is just looking for revenge.)
