As SMN/SCH you notice it a lot with Aetherflow at 50. Cast it, wait until recast timer is up, fire off lustrate twice, wait a second, fire 3rd lustrate and immediately cast aetherflow.
Since you cast aetherflow right after consuming the 3rd it ends up with no buff at all rather than reapplying to 3.

Aetherflow does not get affected by "no effect" on reapply (if you have 1 and recast it gives you 3) and if aetherflow was being applied before the subtraction from lustrate it'd show as 2 rather than having no buff.

For me, at least, I've only seen this kind of thing with instant cast skills or having super horrible (or excellent depending on how you see it ) timing when using a buff skill like adloquium (though not as common unless you try to keep it on a person every time it drops).