Continuity mistake: The coffee mug Mike holds changes position as he and Brick are discussing Cindy's parents.
The Scratch - S1-E7
Character mistake: Frankie freaks out about them not having any real books, which is untrue as Brick has a large collection - he is an avid reader.
Factual error: Even if the cable was out at the grandparents' house due to them getting rid of it, the TV itself should still turn on. Access or no access to cable does not dictate whether a TV can be turned on or not.
Errand Boy - S2-E8
Continuity mistake: After Frankie and Brick get soaked at the car wash, when they're in the bathroom, the towel around Brick keeps flipping between its dark stripe side and its light stripe side, depending on the angle of the shot.