Texas decided that Beard showed an insane lack of judgment by not having broken things off with his psycho gf years ago, and they determined that the odds of something happening again were simply too great for Beard to be retained. and from what i've heard, yes, a decent part of that has come from Beard's own reaction to all of this. once the University realized that Beard wasn't going to come in with his tail between his legs begging for forgiveness, and instead was going to try and plead his case (and according to some he wouldn't even promise that things were done between him and randi), they were really left with no choice but to fire him for cause, before he does something equally stupid in the future.
also, fwiw, while his team probably would have eventually gotten over it and welcomed him back, his players were not happy with the events of NYC, so when the shit continued back at home and even escalated to the point of a DV dispute resulting in a felony charge, the guys on the team were already just about done with any patience they were having for Beard and his insane lover. the guy fucked us.