Board Thread:The Panopticon/@comment-121.45.54.78-20130925110520/@comment-38288735-20191222221250

An interesting point. The only TV story where only one of them appears is Death in Heaven, right? The character is credited as Osgood, and, at that time, we had no reason to believe that Zygon Osgood had stuck around as Osgood, right?

So if I'm remembering all the above correctly, under this policy, it would have to be OG Osgood who is listed as the appearance, as we can't take later works into account, even though Narcissus made it clear that it was actually Zygon Osgood in the episode. There does not seem to be any ambiguity where this could become a "mess".