If you're part of the team, you can grab your own guys and pull them out of a fight.
But if you put hands on the other team, especially if you're not even a player or coach, you've crossed a hard line and deserve a pop in the chops and an ejection.
I've been a guest on sidelines before and not in a million years would I ever consider grabbing or shoving anybody in pads.
I didn't think Greenlaw deserved the original PF for taking a guy down who was clearly fighting for yardage.
And he certainly did not deserve the ejection.
In fact, if he had actually punched that guy square in the face I wouldn't have even dropped a flag on him.