In episode 116 when Justin and Daphne are entering the classroom, Justin has his backpack over his right shoulder. It then alternates between his left and right shoulders. Later it falls off, comes back on, and then is off again.
In the first episode of the first season when Brian pours the water over him, trying to seduce Justin, his hair is wet. In the next shot his hair is dry, then wet again.
The Judge when reading the caption on the Indecent exposure case against Vic: She referred to "The People vs. Victor Grassi". In Pennsylvania the plaintiff in a criminal case is referred to as "The Commonwealth".
There is a hexagon shaped window on the wall between Debbie's front door and the stairs that lead upstairs. In season 1 this window was clear and you could see 'daylight' coming through it. In subsequent seasons the glass panes of this window were covered in gay pride colors and had a non-see-through look. When you see the outside porch and front door of Debbie's house, her house is a semi-detached home with the other half of the house attached to the wall that has the window.
A U.S. Mailbox shown is in painted half red, half blue colors. All official U.S. mailboxes in the United States are a solid blue color.
Distinctive Toronto landmarks can be seen in scenes set in Pittsburgh, Pennsylvania.
In Pennsylvania, where this is to be set, car license plates are only on the rear of the cars. On cars shown in different scenes, license plates are visible on the front as well.
When filming the outdoor street scenes, the observant viewer will noticed the traffic signs, such as yield and do not enter are the Canadian style and not American.
When filming outdoor daytime street scenes, the observant view will notice the cars driving around with headlights. As of 1989 in Ontario all cars manufactured after this time must have automatic daytime running lights.