Continuity mistake: Jeff and Adam meet at their favorite diner for supper. The scene opens first with a street view of the diner, and it is obviously night time. Inside the diner, when the camera is on Jeff, sitting in his usual booth with his back to the entrance, we see the the cash register over Jeff's shoulder, and in the front window behind the register we see that it is broad daylight outside. Every time the camera is on Jeff we see through the front window of the diner that is daytime outside, not night.
Continuity mistake: Timmy agrees to marry Russell because Timmy's work visa has expired and he will have to leave the country. However, in the season 5 episode "Double Down" Timmy states that he has been a US citizen for many years.