Looks deliberate in my eyes. The way he forced his legs into his head is blatantly intentional (his pathetic attempt at covering this to try to make it was accident by falling over is clearly deliberate, too). He should get banned for several matches.
On Arsenal v Man Utd, I think United did deserve the win. They controlled majority of the game, and Arsenal had good couple chances themselves on counter attacks but weren't clinical enough IMO. Bizzare substitution from Wenger on Chamberlain for Arshavin. Arshavin contributed nothing to the game while Chamberlain looked dangerous (and set up assist for RVP's goal)