It's not a question of having a "hard time" believing it. I'm totally willing to believe that Cousins and Thomas hated each other; hell, they might still hate each other, I don't know. I'm willing to believe that Cousins ran Thomas out of town, too... I don't believe it, but I could be convinced.
To me, it's more a question of why should I take some other guy on a message board's word for it? Because he occasionally chats with the old man who works outside the locker room? El Viejo isn't a journalist, so he isn't paid to be impartial; he's going to have his own sensibilities, which inform his perception of whatever he sees or hears. For that matter, none of the posters here are impartial, when it comes to DeMarcus Cousins; some of us claim we are, but none of us actually are. We've all dug in our heels, in terms of where we stand on that dude. Even if I trust the integrity of El Viejo implicitly, why should I give the benefit of the doubt that the other poster is reporting the whole story, and isn't just relaying the portions of information, which he has heard second-hand, that reinforces whatever he's already decided to believe? Like, if El Viejo told buddy a hundred stories about Cousins, and eighty of them are either good or neutral, and twenty of them are bad, and buddy only repeats the twenty bad ones, is that an unbiased account?