Okay, it's starts with post 3832 by zombie which for me is on page 192.
It is basically as you describe it. I thought you were saying that just recently you realized the terms of the bet but you do say within a few posts after offering the bet that you are going to honor the bet based on the terms that if the house impeaches it would mean you lose.
I'm not sure why you didn't just clarify what you meant by your initial offer of the bet if you meant removed from office and didn't want to bet if he'd simply be impeached by the house. There was opportunity to do that without any sort of dishonor. But good on you I suppose for accepting the bet even though it was not the bet you thought you were offering.
Definite props for paying the bet! You absolutely have my respect for that and I was wrong when I suggested you wouldn't pay (although I will say that I always think it's a good idea to get bets like this made online into the hands of a third party because it's just too easy for the loser to back out and or disappear).