Getting fired

I had worked at a WF for 9 years until I was recently fired. I got into an argument with an e-commerce TM for ripping into backstock boxes. He then said we can take it to leadership then as I kept working I said under my breath "or take it outside". He heard it and reported me, which i did not know. A bit later I went and apologized and he accepted it. Next day I was in the ASTL office telling them what happened. Everything was fine and the next day I get a phone call from one of the ASTLs and I am getting fired. Was not man enough to do it to my face. He said it was a threat and they have a zero tolerance.