When Rogue ran away to the train station and
Magneto was abducting her to use her for his machine
Magneto, Toad and Sabertooth ran into Jean Grey and Prof X outside the station. Magneto then grabs all of the guns from many policemen's hands and aimed them back at the officers. After some dialogue, Magneto fires one of the guns, but the bullet is stopped before hitting someone's head. The scene then cuts to Jean Grey looking at the bullet as if she had something to do with stopping it, but Magneto mentions that he can't stop all the bullets.
So did Jean Grey stop the bullet or did Magneto? The bullet was still being driven into the officer's head, which suggests that Magneto was controlling it as it wouldn't be moving forward anymore if it was stopped. But why would there be so much emphasis on Jean during that scene if she didn't have anything to do with stopping the bullet?