I'm OK with it considering he hit him w/ a chair when his back was turned. What they should have done, though, was have Cena grab Daivari before he got out of the ring and FU him, then dare Angle to get back into the ring.
I actually thought that's what they were going to do, since Angle & Daivari took their sweet time before exiting the ring. Kurt left 1st, so it would have made sense for Cena to grab Daivari while Angle still got away. As it was, Cena had to stay down for way too long.