I saw this video on the news last night. When you watch it, it's obvious that Tigger was first trying to step away from the teen but the kid has Tig in an arm lock and he couldn't get away. He either lost his balance or swung to try to get the kid to let go of him ... Either way, it looks like the kid provoked it with that hand behind Tigger's back, which we'll never see. (My first two thoughts were that the kid was either pinching Tig in the back and not letting go, or, as the previous poster said, was trying to pull the zipper on the costume.)