When Phoebe and Rachel are talking in the bar Phoebe says "You kinda just did", but you can clearly see that she's saying something completely different right before the camera changes angles.
Ross tells Mike he doesn't have a keyboard, even though he played keyboard for the gang in The One Where Chandler Crosses the Line (1997), 123 episodes earlier. However, it is possible Ross was lying because he didn't want to play in front of Mike.