If
this reported instance involves a live round detonating in the open ejection port of the duty weapon, while the user was unloading the weapon, it's something I've heard armorers warned about in armorer classes.
It's not uncommon in armorer classes to hear warnings against covering the ejection port of a pistol with any part of your hand when unloading the barrel's chamber. (Meaning like how some people seem to think they should try to catch the ejected live round as it clears the ejection port.)
The reason for the warning against this practice is because if the live round being extracted/ejected from the chamber slips off the extractor while the slide is being pulled to the rear, and the rear of the case tips the wrong way, it's possible for the ejector to make contact with the primer cup.
If this happens hard enough, like when the slide is being energetically yanked rearward, it's possible for the ejector to act as a firing pin if the round shifts so the ejector hits the primer cup.
In one of my armorer classes they showed a picture of someone from a police agency who had his fingers
seriously injured while he was reportedly trying to catch the live round being unloaded from the chamber. When the primer went off, the case was exposed in the open ejection port under his fingers (not contained within a chamber, as intended during firing of the round). Shrapnel. Really nasty injury.
Since first hearing those warnings in some classes over the years, I've always
slowly retracted the slides to extract/eject chambered rounds, tipping the slide to the right (away from me), and
NOT covering the ejection port with any part of my hand (especially fingers), so the live round is helped to fall free by gravity. It falls free of the slide with the ejection port facing away from me (into a safe direction/area), and with the ejected round landing on a soft surface.
A safer unloading practice can be used to try and help prevent this sort of thing.
It reminds me of the time I was in the locker room when one of the guys tossed his duffel bag into the bottom of his locker ... and not gently. There was a muted pop. Opening the bag, we found several loose .357 Magnum rounds in the bottom of the bag ... as well as an empty case, a loose bullet, and a lot of burned & unburned powder. It was apparently just one of those rare instances where one of the loose Magnum rounds he had in the bottom of his duffel somehow managed to have its primer come into contact with something when he threw the bag into his locker, in just the right manner to set it off.