"... At the time the weapon discharged, it was reportedly in a cocked and locked position; that is, the hammer was cocked and the thumb safety was engaged to prevent the hammer from striking the firing pin. A live round was in the chamber ..."
Round chambered, weapons discipline, not! It was reported the safety was on. I wonder if it wasn't?
No, it's pretty standard to have a round chambered with the safety on. For some models having the hammer cocked is also correct general carrying procedure, depending on the firing mechanism the particular gun uses. I do still find it worrying that a firearm would discharge in this manner. Most have multiple internal safeties to prevent accidental discharge during things like a drop from a height.
I am not familiar enough with the details of the Colt firing pin safety, but I believe 'dropped from a height' is not necessarily equivalent to 'pulled from 3ft into a 1.5T magnet'.
Round chambered, weapons discipline, not! It was reported the safety was on. I wonder if it wasn't?