To be honest I can see both sides. Yes it's wrong to head but someone, yes it's wrong for one player to thump another on the ground. Yes if it happened on the street the wrong doers would be arrested. But it wasn't on the street, it was on the pitch in the heat of the moment and I guarantee anyone, those "aggressors" will have shaken hands in the bar.
We are only 3 games into the season, warn all 5 that next time? but now, come on a warning is enough.,
Let's move on.