There is no way that the star of this little clip could know that he was kicked unless it was staged. He wouldn't know what hit him, and the presumption that it was a human foot isn't one that anyone would make.
I think the video is either because he was taking a Vine to show a moody teen with a train whooshing by right behind him or he's using one of the various apps that pull a frame out from the video so he can go home and obsessively go through each one to find the one that shows how edgy he is.
http://www.postalmuseum.si.edu/rms/image…