No, it was listed as a fare in their booking engine online. If they publish or list it, and they let you book it, then they were selling it, glitch or not. Indeed, they let it sell for an hour or so, but it could have been available longer, nobody knows for sure.

If they make a fare available to me in any method, then I would assume I can book that fare. Back then there was much discussion as to when a fare is too low to be true and when it's a deal, right after the disaster one airline was doing $1.00 fares from new York to the West Coast, and that was a real fare to get you on the plane (you had to purchase a $99 return ticket, so round trip was $100). Was the $1.00 a mistake? No, it was a promotion. I still don't belive the Paris fare was a mistake.