The man was making noises in hopes to spook the Moose. The moose was NOT a male in the rut (tho that makes little difference in the bottom line), and the moose attacked and continued to show aggression.
Clean shoot IMHO, I just hope the meat doesn’t go to waste as I LOVE moose meat.
Moose have no fear of humans, and they are so big they can kill you without much effort. This was a wise move.
Also while Moose hunters tend to prefer larger caliber guns, a full magazine can sure do a lot to up the chances of a stopping shot.