Did some digging into it since the topic arose. I contacted a lawyer I know, he primarily does accident and moving violation cases, but he is sharp. I asked him this exactly. "
'If I have an open alcohol container, either mine or someone else' present, in the proximity of a firearm on private property, am I breaking any laws?"
He said no, but if the officer chose to all present could be subjected to a field sobriety test. If intoxicated individuals are present and they are the registered owners of the firearms, the firearms could be confiscated, and that person(s) could be arrested.
Not exactly the same scenario, but a few years back a friend of mine and some of his buddies were shooting at a farm. I never liked to shoot at this particular place due to the lack of earthen backstops, and rough terrain. A round ended up travelling some ways away and struck a Sheriff deputy's house. Damaged a window and some trim. The deputy was home unfortunately for my friend.
Anyways, within the 20 minutes of this happening 4 Sheriffs pull in and take every single firearm on the scene. Shotguns included. After they did forensics and confirmed it was my friends M44 Mosin that fired the offending bullet, everyone else got their guns back but him. He was never charged with anything or had to pay for anything, but he never saw that Mosin again. A case where improper firearm safety catches up to you. I still bust his balls.