Only a good guy with a gun can stop a bad guy with a gun?
'Two stupid grown men' got in shouting match after shooting one another's daughters: police body cam footage
If these guys had somehow killed one another, I could see this as an argument in favor of gun ownership (an invalid argument, yes, but still an argument).
Instead it's just a bizarre mixture of idiotic, ironic, and very nearly tragic.
Perhaps the daughters will grow up to be influential gun control advocates.