Maybe the United agent should be more careful about where they are pointing a firearm. The first rule of firearms safety is ‘don’t point it at anything you don’t intend on destroying’. The owner should bear some responsibility as well. They should know how to make the rifle safe and how to unload it properly. So is it routine procedure to dry fire the rifle when checking it? If the owner would have removed the bolt, all the problems would have been solved.
There's plenty of blame to pass around. I have never liked to dry fire especially in a building.
I saw my Dad shoot a .22 into a baseboard of our house by dry firing. His gun was "unloaded" also.