I still think that this operation wasn’t carried out by the Mossad by the PA - Fatah - which happens to have been trained by both the CIA and Mossad to improve security services and thwart terrorism. Fatah has it in for Hamas, so they could have kludged the operation (and is quite plausible).

That isn’t to say that Israel isn’t infalliable when it comes to taking out terrorists. They have missed the mark before, sometimes spectacularly so, but the size of this operation is far larger than others which is yet another reason to discount that Israel was behind the attack.