Ok, I try to help you. The film just tells a (double) personal experience in the world of street art and maybe wants to give an ironic lesson to the artists themselves much more than art followers (public, exhibitors etc.). It's not a documentary about Banksy, it is about art status through a personal accident. I don't know if I grasped it correctly, but surely the "racial"/language question you pointed has nothing to do with this. I personally think that artists still believe in form of expression open to everybody, even after the hoax.