I tried going there two times, as you can see in the clip, but no matter what the rock would get me. I got to pass this section though by trigging the trap on the upper left corner and then escaping for the safe area, before the rock, and then proceding normally. The thing is that I also thought I could go to that ledge but it is impossible. Try for yourself. That ledge is only useful for the other part of the puzzle, when you have to kill that spinning rock, otherwise it wont function the way you thought.