If the snowball goes over someone that is dead right as they respawn it will hit them and take you all the way back to their base, you can see the dead volibear on the ground who respawns right as the snowball passes over him.
I have experienced this as well.
I have also experienced this bug in the following game. http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1810348471/50501978?tab=overview
I had this happen in my recent game. To be honest, I never liked the re-introduction of snowballs as it throws the balance off ARAM games. That and the cooldown of the effect is extremely overpowered especially if you're continually hitting champs which is always the case if you are being chased as well. Although I use it frequently depending on the champs I use, I highly recommend Riot take this feature out as it has ruined my ARAM playing experience.
