In this case, Tuffy made an offer to buy a book which was no longer for sale publicly. The seller is under no obligation to accept, review, or even address that offer at that point.
Example - You go to a comic book store. You see on the shelf that there's a AF15 you really want at a good price. You're moving towards it, another guy takes it down, takes it to the front. You pass by and tell the owner you'll take it if the other guy doesn't take it, and you leave your business card on the counter. He doesn't answer or acknowledge you as you do so. 2 days later, the original buyer's check bounces, and the owner puts the comic back up on the shelf. Its bought immediately, by someone else.
Did the owner do the absolute smartest, most customer friendly thing? Probably not. Did he break any rules? Assuredly not.
Understand and acknowledge. However, all the arguments against Dan's thread are along the lines of proper Board protocol, good business practice, etc. The same arguments can be applied to the 'Tuffy' incident. I just don't understand why no one cared at the time but everyone is concerned about Dan's thread. Anything goes. It's the new normal. It's not yours until it's in hand. No grade until it's shipped.