The Browns are not the rival they think they are. They have to win sometimes in the division, but that seems to be beyond their management to figure out. You can only feel sad for their fans. The Dog Pound yelps more than it barks.
I think your first point is well taken. That said, the player was clearly upset by the confrontation, especially being called a gypsy. His decision was rationally based on his not feeling that he would be able to control his behavior if he stayed, control in the sense of not winding up detained in some way.
As an older guy, I find it easy to make excuses for Kovalyov. He may have been rattled by the issue of having the wrong color at his board, which was apparently corrected, but it might have felt like this was not a coincidence; he was undoubtedly jumpy because he had scored two upsets, one a huge one; he had only packed for one round, but was starting the third; and mostly, he is only 25 years old. Of course, these are only excuses. He still did the wrong thing, but life goes on; I hope he goes on and does well in his chess career.