Why did Yu send Teal'c back to warn the rebel camp before he was about to attack?

Question

In "The Warrior" (Season 5, Episode 18), Teal'c fails an attack on Lord Yu. Yet Yu allows Teal'c to return to the rebel camp to warn them of Yu's impending strike on the rebels. If this was all part of the System Lord's plan to eliminate the rebel Jaffa; why would he send Teal'c back to warn the rebels, allowing them to escape through the Stargate (which should have been blockaded by an incoming wormhole but wasn't).

It seems like the turning point of the episode was the warning, which contradicts Lord Yu's own plan. What was his motivation to ruin his own attack and allow the rebel Jaffa to survive?

Answer 1

Lord Yu saw the Jaffa Rebellion as a minor problem at best. Lord Yu's Jaffa remained loyal even after his senility, only joining the Free Jaffa Nation after Yu's death and the defeat of all the remaining System Lords but Ba'al.

The real threat, as Yu saw it, was Imhotep. Imhotep was only a minor Goa'uld, but he had access to enough resources and manpower to be a small threat in his own right, and by acting as a charismatic leader for the Jaffa Rebellion, Imhotep had the potential to overthrow the System Lords, Yu included. As such, Yu's primary goal was Imhotep's death. Even though Lord Yu was planning to attack the Jaffa Rebellion's base, there was always a very good chance that Imhotep would escape, whether by ship or by Stargate (which is how SG-1 escaped). Sending Teal'c back to the planet was a decent way of holding up Imhotep so that he didn't escape.

Answer 2

Lord Yu told Teal'c a secret and let him go because it was the crueler option: if you look at Teal'c when he runs through the stargate to challenge Imhotep you see the face of a (temporarily) broken man. Also I believe Yu was the most powerful system lord at that point in time and as such the Jaffa rebellion was merely a minor inconvenience; the target of his attack was Imhotep, a minor Goa'uld with delusions of grandeur attempting to usurp the place of his betters.

It also plays into the Goa'uld tactics: they are big into demoralization and fear, rather than annihilation. Killing all the rebels in that camp would have been OK, but making them flee for their lives and live to tell of the gods' power was better.