[Neus]

This is not a bug. The skill specifies it stops on hit effects of weapons, not other effects. Hayabusa is a set effect. Narcus, while worded in a way that it seems like the weapon's effect, is actually the effect of the status (which only triggers for Narcus). It also doesn't prevent magic bullets.

There was exception I noticed which was Roaring Falcon, which has been corrected.