I have had countless, COUNTLESS instances in Abyssea of using the correct ws but having it dirty, and not once has it ever produced a discernment message when that happens. Not ONCE. And I've seen several atmas drop from mobs without red procs, so I am no stranger to rare Abyssea happenings. So I am also calling POIDH here, tbh

For Voidwatch however, this is true, simply because in VW a spell cannot be dirty.
I'm pretty sure I've heard BLUs complain that their spells will not proc if the spell has an added effect which fails to land on the mob. I never like playing BLU in VW though so I can't cite any sort of personal experience there.