Oh I contacted them, albeit a little late. It was in my watch list but I didn't realize some dummy would bid it up so high.
I said: "I hate to see stuff like this. That stamp is a trimmed #24. I guarantee it."
Their reply: "we are not sure about this stamp, that is why we put ? on the title, but thank you for your info."
I took that to mean that they were not responsible for this disgraceful transaction. To be honest, I have stopped feeling sorry for these buyers. It has never been easier to learn about the stamps we collect or to access plenty of accurately described stamps from honest sellers that would go out of their way to right a wrong or correct a mistake.