The FBI couldn't even get it to improperly discharge through repeated testing. I’m calling baby back bullshit. I’ve been following this since the first news story hit about accidental discharge and each story turns out to be complete bullshit.
He showed the process and made it repeatable. As long as the trigger is even slightly depressed, less than a millimeter- including manufacturing defect or foreign detritus or just external forces- jostling the slide can strike a live round. Even through the safety on.
And that was just repeatable conditions, not the full potential of accounting for p320 uncommanded discharges
Which makes it absolutely a possible explanation for this story, pending further evidence of which gun was fired and when