>> Unless Saddam had collapsed into complete dotage after a massive brain trauma, to predict that he'd be looking for some form of vengeance would take minimal IQ of 0.5 - and one could be a layman, not an intelligence professional... <<
You're presuming he intended to get caught and held responsible.
As it was, he ran terrorist airliner-takeover schools in Northern Iraq, and the media denies he had anything to do with 9/11. So his strategy was quite simple: Get Saudis to do it, and all his sycophants in the US media will say, "why attack Iraq instead of Saudi Arabia." Don't forget: Hussein's number one foreign-policy goal was regime change in Saudi Arabia.
I merely presume that he had typical arab mentality and a knee-jerk reflex. As for him trying have a billt-in deniability - goes without question.