Will we can dream, can't we.
To put it more precisely, he had probable cause to believe that she had drugs, assuming the facts reported are correct. And he didn't just "attack" her for that reason. He ordered her into the inspection station, and she refused to comply. So he went and got her. So far, these are all legitimate parts of the procedure. If you have a problem with that, then you have a problem with whoever drew up the procedures, not the agent himself.
As for what happened beyond that, it gets fuzzy, but what seems clear is that she started fighting him when he tried to detain her. Maybe he overreacted at that point, but realistically, what was he supposed to do? Just let her go? That would have been a dereliction of duty.