If you can't tell by the picture it is two pins (keypin like) protuding from the lock. They are not spring loaded and as far as I can tell perfectly aligned with chamber no 6. Now to the really strange part: When i pushed out the plug with the plug follower it got stuck on those pins - of course, since they are not springloaded. But how on earth could the plug itself fit in there?! The plug looks pretty much like a normal plug and have no millings that could allow the plug to be inserted. Now the plug is impossible to push back in.
Here is a photo of the "pins":
What happened here and what are those pins?