First of all clams, the story is 100% true. Secondly, coaches bitch, complain, and argue constantly. But in 8 years of umpiring I only had one continue the argument at my car. I didn't take it personally, it was more like "good grief man, I don't give an eff, I'm going home" and his red face kept arguing.
Listen man, maybe he'll be a great head football coach, and I only interacted with him a few times 9 years ago, so maybe that's an unfair thing to judge him on, but I think he has serious insecurities and character flaws.