On "Amateur Night", Patrick bursts into the bathroom totally naked. When he and Clint go back to the room and Patrick falls on the bed however, he can be seen wearing underwear. When they retreat back to the bathroom, Patrick is nude again.
On "10/31/1998", one of the characters, the Soldier, was wearing digital camouflage pants. Digital camouflage did not come out until after 2001/02.
On the "10/31/1998" segment when the guys are heading over to the Halloween party, the cars on the highway are obviously more modern for the late 1990s - early 2000s; a Ford Edge is also visible.