You know the old joke about the two guys out camping are surprised by a bear one morning. The first guy pulls a .22 short out of his backpack, and the other says, “You can’t kill a bear with that!” The first one says, “I don’t have to,” and kneecaps the other guy.
My initial thought was that something along these lines happened...and I’m glad that the shooter was merely incompetent and not evil.
I love armchair shooting critics. You've got a bear attacking your friend, likely shaking him around like a rag doll, and you have a few seconds to kill the bear before he kills your friend. You do so, accidentally hitting your friend in the process, and some guy on an internet forum calls you "incompetent".