You know the saying if all you have is a hammer everything looks like a nail? I think that applies in this video in a big way.
He moved closer than he probably would have if the gun wasn't on his hip.
After the moose charged it retreated and that's when he shot it. At that point he wasn't in any danger. I would have moved back and given the moose a chance to move out on its own.
We've encountered a lot of moose backpacking in northern Idaho. Woke up one time with a moose face right in our tent! They are big, they can be dangerous, but a little common sense can keep everyone alive.
For the record, I am from boulder but am also a gun owner, so that's not my issue here! Ha!