He's moved away from his bell while Laura dealt with hers — not unaware of her situation but, in the chaos of the room, only peripherally so. As she moves her way to safety down the non-moving bell, he deals with a shade that's attacked him in the meantime. With his hands full, he'd struck out on instinct with the great bell clapper. Which has proven to be a convenient new weapon, so don't mind him whaling on a shade with it over here.