LB Mimic with W bug

Mimic with W sometimes does no damage.

This has happened maybe 3 times to me so far, and I'm not exactly sure the circumstances besides I try to clear a wave with W > R, and I think when I do it too fast, R's damage doesn't hit.

Then I'm just left in a big minion wave, that should have died, slapping my life away while I try to auto attack them.

Unfortunately I don't have a video.