Yuumi can self cancel W between allies with any ability/active item.

1. Attach to an ally.
2. Attempt to leap to another ally with W.
3. Snap your cursor to anyone but the intended target of step 2 while buffering Q, E, R, Protobelt, whatever.

Expected Result: Yuumi doesn't try to kill herself by cancelling her own W. Actual Result: Yuumi will cancel her W mid flight and deploy whatever you pressed.

Video evidence linked (sorry for the lack of cursor which is maddeningly important here but whatever).

More evidence incl R, E https://www.youtube.com/watch?v=XVc1MyY3Srw