Nynaeve, Elayne and Egwene, hard at work in the kitchens, are approached by the Amyrlin curious about an update on their progress. Egwene and Elayne get carted off under some pretense the Amyrlin concocts to minimize eavesdroppers to get their mouths washed out with soap, leaving Nynaeve to give the update. Else Grinwell, who pointed the three women onto the path of finding the belongings the Black Ajah left behind, is revealed to have been dismissed from the White Tower weeks ago.
Nynaeve tried to swallow the lump that formed in her throat. The Amyrlin's words made her think of bullies taunting smaller children. The bullies were always so contemptuous of the littler children, always so sure the small ones were too stupid to realize what was happening, that they made little effort to disguise their snares. That the Black Ajah was so contemptuous of her made her blood boil. That they could set this snare filled her stomach with ice. Light, if Else was sent away ... Light, anybody I talk to could be Liandrin, or any of the others. Light!
Nynaeve, The Dragon Reborn, p. 274
The Black Ajah is insanely overconfident. If murder and theft wasn't enough, overconfidence and swagger about it is twisting the knife. From a plot perspective, it's necessary to drive the women to follow them to Tear. From a leadership and organizational management perspective, it's an absolute Achilles' heel. Assuming that they're unmatched sets them on the path for their demise. Part of what keeps top performing organizations on top is their drive to keep pushing the limit. An element of that is the assumption that some competitor is "better, faster, more." Having the idea that the organization is untouchable leads to complacency. Complacency becomes infectious; starting in one small area and rapidly spreading; product quality drops off and, by extension, revenue. Although, if the Black Ajah went out of commission, the world wouldn't mind.