There is not really a big mystery here.
Shit happens; the BO isn't here to run interference. Call it a learning curve.
Either the then current baker (#7811) -OR- another BV got the "oh, shits" and LOCKED the thread and either didn't know how, or didn't care to, unlock it.
Then another baker came along and in his haste to help, inadvertently mis-numbered this thread.
For the BV reading this that knows how, the correct fix for the current situation would be to delete the stub of the locked thread and then REnumber this one as 7811.
With that done, the next one will be 7812 and life will be good again.
Nothing wrong with a learning curve, as long as whoever didn't know how to unlock that thread learns from the experience and the collective BVs recognize what happened and learn from the experience.
I realize it can be intimidating at times. God Bless All of You.