I do agree with you to some degree here. In the minute leading up to the incident, he does shake his hands around a lot, making a lot of wanker gestures, and it's not completely different from the gorilla incident. After viewing it many times I am leaning towards it being a gorilla impression, but I don't think it is set in stone. The plane gestures in other clips are much more clear cut.
I do find it a little disturbing how the online mob can find him guilty to the point of involving his kids in the matter. I don't condone racism in any way, but do you deserve to have your life ruined over a 1 second incident because it happened to end up on television? I think a lifetime fan on Citys end could be fitting, but the whole ordeal of tracking him down online to afflict as much pain as possible doesn't really speak to me.