Sounds like something political in nature.
Essentially, you are the new guy, upper management saw a disruption in the workplace (whether or not it was your fault), and took the easy route and terminated the new guy for the sake of the greater good (to shut MS. ____ up).
"I admit to losing my temper after that, being the "verbal altercation" in question". This can be the scapegoat upper management could have used, depending on what you said. Either way, all it takes is one time to loose your temper to change everything. I have those moments sometimes, but I tend to hold my tongue.
Either way, sucks that you got the short end of that deal and I hope it all works out in the end.












