...that George Johnson "could" double on baritone, and did so occasionally during live performances. Apparently, though, it is just as you have said here: someone looked at this particular photograph, and then the personnel was entered into Rust with every doubled instrument mentioned, whether or not these instruments were actually heard on the records themselves.
It is also true that earlier personnels do have a habit of being passed down, even when they have been refuted (maddeningly so sometimes) - for instance, the Gil Rodin Crown session of "Loveless Love". I've had the HRS issue for many years (both takes were on each side of this 78 rpm dub). For years the books have had "Benny Goodman" as clarinet here, but it is Jimmy Dorsey. I have not checked the new edition, but wouldn't be surprised if BG is still mentioned. Errors like these take many years to clear up, if they ever do.