I always thought when a new mag gets put into a gun, it needs cocking to load the first round into the chamber ? I could be totally wrong though. I’ve no real world experience with any firearm.
Edit. Yeah, what Rroff said.
Basically, there shouldn’t have even been a round in the chamber, especially off duty. Just seems daft to have a round chambered. I don’t think glocks have any manual safety either.
It should be chambered when you carry it. I carry a glock 26 or 19 and it's chambered ready to go. No safety and nothing holding it in the kydex holster other than friction.
Glocks have an internal safety besides the trigger safety so they are half cocked when you rack the slide. It cant go off when you drop it. When you pull the trigger it sort of cocks it the rest of the way and fires.