Except maybe for current comment (not really, HN just has more replies on anything these days), nothing actually turned into flamewars, most out of his few "flamewar" comments over many months barely had any replies at all and were just flagged. It seems you are labeling them as flamewar just so you could justify banning him. Possibly because he expressed opinions you consider "politically incorrect" today and you want to suppress such opinions on HN.
Also you can't claim he ignored your many requests to stop, because you never made a single request to stop what can be interpreted the same way by both of you, he probably thought he followed them. Again, you were using this as manufactured justification to ban him.