So if you haven't seen the movie yet and don't want to know any more spoilers than that there is a scene involving rock climbing, stop reading now :)
So someone actually wrote up a somewhat detailed list of exactly the kind of issues that doctorskuld and i were thinking of.
The Real Problem with The Dark Knight Rises? The Climbing Scenes Make No Sense
My favorite bit: "Why do we fall? Because we make terrible, terrible decisions when attempting to read very simple climbing routes."
Actually, i didn't think about the belayer at the time, issues #2 and #4 are the ones i thought of. It sure looked to me like any experienced climber should have been out of there in about five minutes. I myself am not that experienced, but it didn't look that much more difficult than stuff i've seen others doing, and this person who seems to be an experienced climber appears to agree.
One could argue that the people in the prison may not have been experienced climbers, but seriously, what else do they have to do to spend their time on? They might not have been experienced climbers when they first got tossed in, but a couple months or years later...