Bet he was looking in the mirror doing his “Barney Fife quick draw”, while giving his steeliest Clint Eastwood glare, and things went downhill from there.
It is possible, but most police accidental discharges with Glock pistols occur when they attempt to re holster the pistol with their finger inside the trigger guard. It is not so hard for me to see how this might have occurred in a bathroom, say with trying to readjust the pistol and holster when refastening the pants.