I didn't see a problem with the hit. He was within a step when the ball was thrown and he made a good form tackle to the torso without any shot to the head. It seems like most football fans across the country are in agreement.
If you look at the freeze frames all the Packers media and fans are posting, it obviously looks like Barr ran five yards to get to Rodgers after the ball is already out. But watching it in real time (and even in slow motion), Barr is going for the torso to wrap him up. Further, we've all seen Rodgers to his little pump fake to stop defenders and then run for 10 yards. I'm not certain Barr saw the ball come out and he was trying to prevent that Rodgers scramble play like the one we saw beat Dallas by wrapping him up.
I generally like Rodgers as a player and think he's entertaining. I'd love him if he were a Viking. But he does seem to think he's above the game sometimes. Sorry, Aaron. If you want to play quarterback, especially if you want to play the position the way you do as a scrambler and improvisor, you're going to have to take some hits occasionally. Unfortunately on this one, your arm was in an awkward position as you came to the ground. Those are the breaks.
