Varus' Q possible bug?

I played Varus recently and when I shot Q, it went in a different direction than my cursor was. At first I thought that it was me and I only misanalyzed my cursor's possition, but then it happened again and it was even the same angle (~30°) and also left side. Might be an interaction with slows, not sure.

Anyone other with similar experience? If so, could a Rioter look through it?