{Gameplay} Kassadin Q Bug?

Last game on Howling Abyss as Kassadin, I Q'd a Lucian using the Culling and it didnt stop his ult. Pretty sure the culling is supposed to count as a channeled ability, but I could be wrong. It stopped the Velkoz and Cait ult, but didn't seem to want to work on Lucian. Its a minor bug, and probably easily replicated.