The 11 got exactly what he deserved.
As far as Byron's penalty, if they don't call it during the race, there shouldn't be a points penalty after. NFL officials miss calls all the time, and they don't go back a day after the game is played and take a touchdown off the board.
Besides, if Byron had retaliated under green, if the 11 smacks the wall and is out of the race, and if Denny gets concussed.....would there be a penalty for that? History says nope, absolutely not. Drivers rough each other up all the time, which usually causes someone to lose track position. Welcome to auto racing.
And what do you call Hamlin riding around Gateway at half speed in front of Chastain? No penalty, and another case of Hamlin being really lucky he didn't get Kenseth'd straight into the outside wall.