When use bow while in a boat the passenger is hit instead.

So my horse and i going on a trip with a boat, my horse and i was on the same boat, and then there was a creeper show up in front of me, so i pull my bow without jump off from the boat, i wanted to kill the creeper with my ultimate strong bow, but the bug make my horse died instead the creeper, pls fix this mojang, this bug make me accidently killed my best friend :'(