This is definitely a bug after reading everything. It has to do with the game not alleviating the property tags properly, which happens all the time in the game.
Actually didn't happen in Patch 7, but started happening in Patch 8. For example you could kill the Hag, but all her property would still be flagged as hers. Same is happening here, despite the doors not being red. And since the doors are tied to the quest for Sazza, it does not update the tag.
I'd report it ^^
