With Danae’s Long Form COLB and MestaMachine’s pointing out that the time period was during the Y2k fix, with your research on the ‘File’ versus ‘Accepted’ data fields, it looks very much like a computer glitch caused the data field errors too subtle for a clerk to catch before it was mailed to her.
I would willing to bet on it.
Now let’s figure out how the 2007 stamp got on the back in 2000.