Woad Darius W Animation Doesn't Play [Gameplay]

Reposting here as per Support's request.

When playing Woad Darius, if one presses W and then autoattacks, the mini-spin animation occurs normally. However, if one is in the midst of autoattacking and presses W immediately after using a normal auto, NO animation will play, but the W attack will go off. This is actually a little OP for a laning situation, as by all appearances, you are only hit by a single auto, even though you took the damage (and slow) from two. I've reproducibly recreated this in a custom game and confirmed that it is not a local graphical bug (the other people in the custom game observed the same thing.