I don't care if he was the owner, your in a hotel and they are accustomed to late check ins. A security personnel should not point a firearm any anyone until he knows he is threatened not his personal property.
I would of left and called the police and if he must carry a fire arm. I would think he would carry something a bit more conspicuous than an AK. I'm all about gun rights but that is not good business. Its like having a growling dog bearing its teeth at a petting zoo. It may not bite but I still wouldn't want to see it in there.