Foreign Advisor Tech Screen Error

I'm playing a game with the "No Tech Brokering" option and I've noticed that the Tech screen displays techs that techs are displayed in the AIs "Can Research" column that shouldn't be there. For instance:




Notice that Alexander and Saladin both have Monotheism listed in both the "Can research" and "Can't Trade" columns. Also a number of AIs have Monarchy in their "Can research" column and it's 1375AD and all have Longbows defending their cities.

I'm pretty sure this has something to do with the AIs having received techs in trade with the No Brokering option.

http://forums.civfanatics.com/uploads/105859/TechScreenError.CivBeyondSwordSave

I'm seeing the same thing. I also have "No Tech Brokering" on, though I'm not convinced that matters.

At least in my case, the "can research" column seems to be displaying techs that I don't have some of the prerequisites for? For instance, I skipped Priesthood, and now most of the AIs have the three techs that require Priesthood - Writing, Code of Laws, and Monarchy - in their "can research" entries, even though they actually already have those techs. And if I use the Worldbuilder to award myself Priesthood, those false entries disappear.

There must be something more to it, though, since those techs don't show up for all the AIs.