when she mentions needing to be cured to the Kithrak, he basically looks at her stupidly
Lae'zel is a zealot ...
She would not recognize a lie, even if you will slap with it over her face.
Whatever her teachers said, is the truth in her eyes ... no matter the reality.
I actualy do believe Kithrak in this one, that there is in fact no cure, and whole story about purification is only fairytail for foolish younglings, to rush back to their créche, and being killed before they spawn another forsworn enemy of their kind.
How did he say it?
"Only in death are infected cleansed."
After all, Gith are Evil race ...
Ruthless, cruel, and effective. :P