In this episode, Ted and Marshall have an argument on a Halloween party that Ted forgot to give Marshall and Lilly a wedding present and it shows the Slutty Pumpkin at the end. However Ted met her several years before season 1, when they were not even engaged.
When Robin bets James her ring, she goes to put it on the medium sized stack of black chips but it falls off. Next time the stacks of chips are shown the ring is on the high pile of red chips. It does not show her making any motions to put it there.