Katie should have taken the opportunity to send off another volley of hexes but instead she paused momentarily to see what would happen, if he'd be able to pull out of the spin the curse had put him into.
Which was entirely stupid of her.
"Fucking hell." She reached out for the bombs even as they went flying out of her reach when he summoned them. She shot off towards him following the bombs praying he wouldn't catch one. He managed to catch one and the others fell to the ground - she might have been able to catch one if she dove for it, but that would leave her incredibly vulnerable.
So she continued racing towards him as he flew towards her and then threw the bomb at her. And everything slowed, it was just like a match. Katie focused on the bomb flying through the air towards her, just like a quaffel and she pushed forward more, enough to reach out and grab it out of the air and just as quickly toss it back towards her attacker.