Skarner + Aftershock bug

Aftershock will activate on Skarner when using his R even if it cancels (like if target moves out of range/sight) It happened to me when I tried to ult a Zoe out of her portal (which feels amazing when it works). I pressed R too late though, so instead she popped back to her starting point and Skarner shouted "FEEL MY STINGER" but nothing happened (lol this happens a lot for Skarner tho). Aftershock activated even tho I didn't CC anyone.