In the video it looks like he pointed the gun at the snowboarder, which is brandishing. No point in that for a simple trespass.It's a bit extreme, but why should a man get in trouble for carrying a rifle on his own property? He didn't point it at anyone or do anything that can be considered brandishing.
Just an old hag sick and tired of people skiing/snowboarding through his property.
$100 says that snowboarder will never go on that guys property again.