I don’t know what make & model pistol was involved here, but odds are the gun was being played with, and the trigger got pulled.
As far as action designs, IMHO they should be using DA/SA autos equipped with hammer block safetys. These can be carried loaded with one in the chamber and the hammer down, safety on. In this condition, even pulling the trigger and dropping the hammer wil not fire the gun.
When needed, just push the safety off, and pull the trigger.
The more knobs, levers, buttons, you add the more worthless, but lawyer and liberal Politburo acceptable, the gun becomes. Your finger is your safety. Don't put it on the trigger if you don't plan to shoot, how's that?
I have a .45 revolver by my bed. I get the benefit of .45ACP modern bullet design, and the simplicity of point click interface. And moon clip reloading. And that sweet S&W trigger. And nearly infinite reliability.
The typical Sig Sauer is a good example.
Somebody will correct me if I'm wrong, of course, but I think Sig makes a series of Double-Action-Onlys, as does Glock, mainly to satisfy requirements of law enforcement agencies. Maybe military also--not sure.
I don't know how much safer a DAO is, but statistics may come into play here. A LEO handles his weapon orders of magnitude more than the average civilian owner, so every little bit of improved safety would in theory translate to measurably fewer ND incidents.
Having once owned a Sig of the aforementioned SA/DA type, and now owning a relatively cheap DAO, I find the trigger pull on my particular DAO to be strong enough and long enough to make it difficult to fire accurately. I know for sure it's not going to fire without my finger on the trigger, given just the least bit of care in handling or packing.