This is the part of the story I've never understood. Unless Wilson took part, directly, in the forgeries.
From what little reading I've been able to do today about this matter, my biggest fear is that Fitzgerald hasn't pursued this angle, among others.
Yes, either he directly took part in the forgeries, or his wife knew about them and discussed them with him, because she belonged to the circle of rogue CIA operatives who were responsible for the plot to embarrass Bush.
That would explain how he could get the timeline so very wrong--because he knew about the forgeries months before they were delivered and made public.