I just got this from someone that I consider a very reliable source, take as you will but I believe it:

Early in practice as the defense was running plays (without an O), Furr stopped his run back to place with about 20 feet to spare. This is a pet peve of Rhoades (who has several pet peves, btw). Rhoades let him and every player on D know it with, if it happens again from any player that the entire D unit would be punished.

When running plays against the O, that were to be stopped by a defender touching them, he was run over by Eric Smith after catching a pass when Furr was in place to make the tackle but wasn't pursuing to finish with a tackle. Smith then stood over the top of Furr and said something. Furr jumped up to defend himself, said something and then turned to walk away. That is when Smith grabbed him by the jersey with a don't walk away from me bro. An altercation broke out, but was nothing but a spitting contest.

Later, Furr again fell short of his place before he started to loaf. This is when several of the starters jumped down his throat. Again a spitting contest at first until Furr apparently said something and was hit in the face by a fist. Furr then tackled Ethridge but was broken up quickly by players and staff. There was no piling on. From what the spectator said what he saw was players trying to stop it, not add to it.

There were rumors, that Furr was unhappy two weeks ago, but no confirmation as to the truth and about what. From what I take of the entire situation is that combined with the fact that he was already unhappy added to a series of unfortunate events that escalated that Furr felt his world was crashing around him. I believe he and the team would have been fine if he felt he could face them over the following couple of days. Yes, there would have been some uncomfortable moments but they would have passed and we would have all called it "male bonding". But Furr, didn't want to be placed in that situation and felt that it was his best time to pack up and go.