Not really. I would bet he grabbed the guys arm when it was down (both his and Skinhead.) Skinhead then raised his fist/arm up and Kerry's "went along" for the ride. See how his (Kerry's) is externally rotated? He grabbed Skinhead's forearm(hand would have been unmanly) and Skinhead raised his fist/arm with Kerry's still attached. Bada-bing.
It is still weird though isn't it?