I don't think Ray Allen is a shooting slump. I think the team has gone away from him and it has affected his game. His shot is looking good. Given, some nights it's off, but I think his shooting is there.
As for Rondo, of course the crap he was playing until recently affected Ray. One of the key aspects is that Rondo is often missing Ray in transition, or waits too long to give him the ball. Not always a bad play, but when concerning Ray it affects his game.
But Rondo is not solely to blame here. Doc is to blame, Davis is to blame, etc.