Factual error: Sue's birthday isn't actually on Leap Day as this birthday is her 15th (in season 4 she celebrates her Sweet 16) and Leap Day birthdays are multiples of 4. The closest leap day birthday in this sense would be her 16th.
Continuity mistake: The popcorn Frankie is eating off her shirt moves around from shot to shot.
Bad Choices - S3-E6
Continuity mistake: Mike's pants are already wet when he goes to turn off the water.
Continuity mistake: When Frankie writes the list and hangs it on the fridge, all the handwriting on the list keeps changing in the following shots.
Continuity mistake: When Brick is first shown in the garbage can, there is garbage up to the top of it, but when Brick manages to knock it over while still inside, there is much less garbage in the can.
Continuity mistake: When Sue is sitting at the counter waiting for the cheerleaders to call, the phones lying on the counter go from being close together to being spread out like a fan throughout the scene. Every time she is shown the phones are laid out differently.
Continuity mistake: At first, it says Brick would live one month at Ferguson's but here it says Frankie would stay one week with him.
Continuity mistake: When Mike reveals that he has a cat at The Quarry, the digital clock in Frankie and Mike's bedroom goes from 2:58 to 3:02 in the span of 1 minute. (00:04:00)
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.