Interesting. Seeing as how the Sigs we carry don't have a safety.
SIG can be carried hammer-down with a round chambered, though, as they have a decocking lever. I doubt there are many instances where a 12ish-pound double action trigger pull will be triggered inadvertently (knock on wood). Carry a Glock with one in the pipe and you're automatically on its 5-pound pull. All the "safeties" are tied into the trigger; they seem more concerned with securing the weapon if dropped than preventing inadvertent trigger pull like a true mechanical safety. Supposedly this was for the convenience of the first law enforcement personnel to get Glocks, as they were used to revolvers.
That said, though I own a Glock 19, I wouldn't consider it for concealed carry or ever leave it with one in the pipe. The only safety I'm totally comfortable with on it is the one attached to inboard side of my right hand . . .