There was a story about Riley Cooper getting into a fight that had to be broken up by several Eagles players, all things which are vague and therefore technically true. The insinuation is that someone dusted up Cooper for his aggressive use of the n-word earlier in the year, but this "fight" occurs in NFL practices almost every single day. Cooper was going for a ball while Cary Williams defended him closely. They fell to the ground, pushed and shoved, and were quickly separated.
Were there any leftover emotions from the summer? Sure. But this was more a product of two dudes working hard in the summer heat just before the season begins. There isn't a whole lot to it.
As for the regular season, when guys haven't had a chance to get to know Cooper, get over it or forgive him? That's a different story. If anything, Cooper might want to thank Williams for the extra-effort in practice.