indeed, this is the major problem with any american gun argument is that there are too many examples of this level of basic idiocy when it comes to the fundamentals of firearm safety.
very few guns are complicated to use (in the basic sense of loading/unloading and firing), so there's no excuse.
Even with firearms safety very much in mind its possible to overlook things as well - for a long time I just kind of assumed as long as the gun was angled (horizontally) down range and pointing downwards (muzzle) everything was fine - wasn't until relatively recently I became aware of "dangling" as in you can be accidentally sweeping your feet without even thinking about it. (And that assumes there is nothing below you of consequence such as you are on a higher floor of a building with people below).
Having guns around kids in that context really isn't a good idea.