That doesn't contradict the idea of Malak using it later on. After all, Revan, a foe he easily incapacitated and ragdolled with the Force, bested him in a duel twice in a row on the Leviathan. Malak engaged his former Master with a lightsaber at first, but had to resort to the Force to end the struggle both times. It may have been the same with Bastila - perhaps out of desperation, he was forced to place her in a stasis field as he had done previously.
Malak may actually be that shit. 🙂