First of all, he may have had words with you in front of passengers but you did call him an "Idiot" in front of all those same passengers first! You also raised your voice to him saying that you were not imagining it in front of all those passengers. That was very wrong and very out of order! If you were indeed a commercial pilot you would know yourself never to do something like this. You also could have created a very nervous atmosphere for the fellow passengers at the gate. Now having said that he clearly did not react the way he should have but then not all of us are perfect human beings. But then, you did call him up in front of all his passengers who he is responsible for and proceeded to partake in childish name calling! You would have added undue stress to the start of that pilots day which would have lasted a lot longer then the event itself and could have created a its own sequence of events that could have led to safety being compromised, heaven knows we have seen enough cases of events where pilots where stressed by outside situations jeopordising their judgement!
If that had been any other situation outside of work you probably would have received a thump!