The absurdity of the premise behind "a gun that can't get turned on its owner" is almost beyond the pale.
Because guns don't generally get turned on their owners. It isn't a common occurrence, not here in the US, or anywhere else. If it was, we'd see a lot more "man shot in home by intruder with own gun" than we do.
It's an urban legend, up there with other silliness told by high schoolers to get their dates to snuggle close.
There is one and only one pragmatic use for limiting who can use a firearm: restriction of effective force into the hands of the "right people". The right people will always be those who have power, and want to keep you from it. Consider that for a moment before embracing so-called 'smart guns': the people pushing these want to restrict firearms to only the military and police.
That's worked out so well for people throughout history already, hasn't it?