I have actually seen that happen a few times. Ray's ball handling skills have gone down a bit in the past couple of years. I am always worried about a TO when Ray has the ball in transition, and tends to either get trapped in the corner / sideline or just flubs a dribble. I could see that being a source of friction. Rondo doesn't want to chance the turnover, but Ray still thinks he can handle the ball like he did when he was an elite player.
I have to say though, I was impressed with Ray's def during our playoff run, he worked hard at being a pest, and was way better than I expected on D. I really like Ray as a scorer from the bench for us next year. If we could get / stay healthy a bench of RA, Bass (if a better 4 is found), Green, Wilcox, MP, Dooling, JJJ, Moore could be decent. Def some scoring in there if a good rotation can get worked out.
I noticed during the PHI and MIA that there were probalby 1-3 times a game where Ray would come off his patented battery of screens with what looked to be his normal (or close to normal) separation and Rondo simply looked him off.
I see a lot of it going the other way. Ray will get a rebound and bring the ball up when Rondo's calling for the ball, or PP will avoid passing the ball to Rondo when the defense is on him and Rondo's calling for it and try and run a play with KG or Ray against a stacked defense.