"Stuxnet wasn't the only spanner in the works"
Spying 101 : keep your enemy looking for threats, whether they exist or not.
Of course he's going to say that. Mossad is full of actually competent people. They know that you keep your enemy under pressure, so that the enemy makes mistakes that can compound whatever it is you have in waiting, or make it easier or better to unleash at the right time.
Of course, if I were Iran and Mossad declared that they were done and didn't have anything ready, I wouldn't trust them either . . .