The keeper had possession of the ball when she was hit. Collar bones aren't easily broken... it was a foul, and since the keeper had obvious possession it should have been a card whether it was an accident or not.
What happened happened and a card would have done nothing to protect the keeper after she got hurt. A card would, however, have influenced the game, penalizing GPS and causing them to make adjustments (including taking the player who hurt the goalie and later scored GPS's goal off the field). Of course it is possible that another GPS player could have scored, but either way, the game would have been different.
After losing their goalie to an obvious foul, (whether on purpose or accident) Baylor received only a free kick from their six (which certainly didn't penalize GPS in the least.) Nothing, the ref could have done would have brought the keeper back, which is what Baylor truly wanted, but the call he should have made would have influenced the outcome of the game.