Swains Q (now a zone...kinda) doesn't trigger spell thief?

But Morgana pool still does. Is this intended? Now that he has a semi-AoE slow I was going to give him a run in support a bit, but I guess since the bird is still DoTing one target in the zone, it doesn't trigger spell thief since it's a DoT? Just wondering if this is intended or not, since it felt awkward to me when it didn't trigger. Anyone else try this?