launcher unable to uninstall

At a friend's server, I rode a minecart down to his house, and when I got out, the minecart was making its sound when it stood! I destroyed it & it kept playing. I then got out of the server & it still kept playing

I was making a minecart ride meanwhile I was shooting mobs with a bow. When I saw a pig under me, I shot the bow and the arrow instead hit and destroyed the minecart! This also happens to boats.