Let me just preface this post by saying that the way Rose was playing last night, I think he was unstoppable.
With that said, Rondo was awful defensively, and here's the reason why. When Rose was driving Rondo didn't do much to keep him away from the basket, which should be his main responsibility against Rose. What he did do, is that he stayed in front of Rose, at times quite well, but once Rose was within 10-15 feet from the basket, Rondo stopped trying to stay in front on him and instead planted his feet and tried to swipe the ball. It's as simple as that, and it was his main flaw last night. On just about every single play that was the problem. His problem wasn't going for steals in the passing lanes or anything, it was simply him stopping moving his feet to try to get a steal within 10-15 feet from the basket.
It's freaking dumb defense, and as great as Rondo was last night, and it really pains me to say this because he was the only one that played with a lot of energy the whole game, he was very toxic defensively, and other than his individual offense, I don't feel he did a good job running our offense (but I'm not going to give him much crap about this because he put on a good show and kept us in the game).
With that said, the bigs need to do a better job against Rose, but hats off to Rose because he really had a fantastic game.