She said after the SP that she didn't know what happened with her 3F--that makes me think that her problem is technical, not mental. No "I was nervous" or "I got caught up in the moment." I could be wrong, but the fact that it's the 3F and none of the other jumps (until the FS, where she was clearly insecure) suggests a tiny detail that somewhere, somehow got overlooked.
Also, I refrain from making huge umbrella statements like "she is not mentally tough enough" over the results of one competition. I like to keep in mind that an entire thread was dedicated to questioning Gracie Gold's ability to handle pressure after Skate Canada, and she made all of her career-harbingers look foolish after CoR.