granted sweeping someone with a firearm isn't good, especially at the range where you're supposed to be facing muzzles downrange only. But if you're showing a friend a firearm at home or something, and you conspicuously clear the firearm first and lock the bolt before handing over or show them the gun, it's not too bad. Especially if both of you have the common sense to maintain trigger discipline.
Not trying to start an argument here. Nor do I want to get into how one has been trained in safe gun handling. And how one practices safe gun handling. So I will just state how I was trained.
When I was around 8-10 years old (Mid to late 60's) my father took me to a 3 or 4 evening class put on by the NRA that dealt with life safety issues. The class dealt with items like what to do if you get lost while hiking or camping, proper use and handling of knives, how to deal with snake bites and of course how to safely handle firearms. This course also included how to shoot and culminated in live fire and activities for young people.
I was trained that while handling a firearm, you open the cylinder or rack the slide and prop it open so you can see it is unloaded. If it is loaded, unload it. In other words it is not enough to just see an open cylinder and slide I won't get into the specific reasons for why as I am sure some here will want to debate these reasons. However, I was also taught a couple of things. Like never accept a firearm that you cannot visually see has an open cylinder or has an open slide. But the gun is still considered loaded until it is in your physical posession and you visually check that it is in fact unloaded. Another thing they were adamant about was once that firearm left your posession you consider that firearm loaded. Combine this with never pointing a gun at anything you don't intend to shoot then sweeping someone with an unloaded gun is unacceptable. Under any circumstances. Which also means allowing oneself to be swept is also unacceptable under any circumstances IMHO.
I understand that this was a long time ago (50 years) so maybe gun safety rules and training have changed over the years. I don't know. Maybe one of the certified NRA instructors here can update me on the more recent gun safety practices.