Yes, Soo Lin Yao and Jennifer Wilson are both clever, but doomed. I was listening for it in the rest of the episodes, and the clearest place was in Reichenbach, but I can't remember without a transcript if Sherlock himself says it: John tells him not to be clever at Moriarty's trial (Sherlock fails at that), and then Moriarty uses the term a lot in the rooftop scene. Which, again, implies that to be clever is to be doomed. Somehow. IDK. I need to think more.