Someone walked into him. The backpack was knocked down his arm, but not to the floor, and he wasn't hurt in any way.
"No need for apologies," Jasper said quickly. "Are you alright?" he asked, not noticing that the flier had been dislodged from his back pocket and floated to the floor. The woman seemed fine, if a bit distracted. "It's very busy here today..." he added, as if that explained any possible collisions.