It doesn't happen very often but a few yrs ago back home in NFLD a moose popped out on a trail and charged a guy. Narrow trail so nowhere for the guy to go he had to bail and climb a tree. After so long in the tree he phoned his brother on his cell and he then came and shot the moose. The guy was in the tree for 4 hrs by the time it was finished. His sled was a write off as the moose kept smashing it over and over. They called wildlife who came and took samples and sent it away to be tested. Never did hear if there was something wrong with the moose. So it's rare but it does happen. That being said I do think the guy could have backed up and avoided the situation But I wasn't there so maybe the video doesn't give the whole story. He still should have put it out of it's misery before leaving it there to suffer.JMONot sure why the moose was so aggressive, probably had a good reason. But you can rule out the calf scenario since that moose is a bull. Look at the bell under its throat. Cows don't have such a big bell. Also, if you stop the video at 34-35 sec, you can clearly see where his antlers were before they dropped. Possible scenario is the bull may have been just chased or attacked by wolves or a cougar, making him quite aggressive. Fight or flight when it comes to that. Something obviously made him pissed off. Sledder was at the wrong place at the wrong time. Or maybe buddy on the sled was chasing him down the trail for a ways, moose finally had enough. You don't know what was going on before he posted the video. I'm not an expert, but I have never heard of moose attacking "just because." Either way, it is mind boggling that he was packing a hand gun. Cougars in the area?