Though Brandon said he had to fill in a hole in the middle, and I was thinking it was that bit about the Two Rivers, partly because of the issue you mentioned, and partly just because the language seemed somewhat clumsy (using 'operation' twice when RJ likely wouldn't have used it either time, etc.) Brandon also has a tendency to express POV thoughts through questions. It's not that RJ never did that. Brandon just does it so often it seems like a crutch. That said, it's technically possible that Slayer wasn't 100% honest to Perrin—he might have wanted to play along with Fain's game while hunting him, and it seems he shouldn't have been too hard for Slayer to find at the time—and it's also technically possible that the error (if it is indeed an error) is RJ's. Not only was he known to make them, he was also very ill when writing AMOL.