in other words, if you have a person in your family that is mentally unstable, and you leave a gun on top of the table and this person takes it and shoots 20 people, can you just say "well, the issue is that the person was mentally unstable"
If a person leaves a gun on top of the table, that person is mentally unstable or and idiot to begin with. I live in the USA, I need one more year to be able to purchase a gun, I've already taken several classes on gun ownership and one of the first things you learn is proper handling and storage of a gun.
You learn to Always treat any gun as if loaded and ready to fire ACCIDENTALLY.
A person who leaves a gun on the table is an idiot to begin with. you never leave a gun unattended.
Gun ownership, gun handling, gun storage is a serious thing.