Being slow due to it's size and weight, Christa took the hit, but retaliated with another Heavy Slam as Azriel, whose mind could think faster than the Lopunny could move, had already prepared for the counter attack, and countered her Attract with Magic Coat, bouncing it right back at her.  At such short range, and presumably not expecting it, there would be no way for her to react fast enough to get out of the way in time.