Visible crew/equipment: When T.J. is playing basketball in the garage, before the helicopter scene, you can see the boom mic fly across the top of the screen for about 2 seconds.
Book Smart - S2-E8
Continuity mistake: The word "Puritans" is written differently on the chalkboard between shots, in the scene where T.J. is discussing Puritans with Mr. Delk.
Continuity mistake: When TJ records his messages for when his dad comes up to talk, he says "You're right, I just need to sleep on it". When Marcus plays the tape, TJ's voice says "You're right dad, I just need to sleep on it".
Other mistake: When T.J. types in his height instead of Floyd's while searching for his dad's date on the computer, he never pressed the "Enter" key.
Other mistake: In the beginning of the episode the Chem teacher tells the principal he can't take over for the other teacher's 5th period because that's his only free period but T.J. later on during the trial says Mo probably left his playbook during 5th period. (00:03:17 - 00:12:26)
Continuity mistake: When Yvette was talking to Victor, while she was looking at his pictures, her water is in front of them in one shot but in the next shot it's gone.
Continuity mistake: At the beginning, while Yvette is talking to her friends, her bottle cap keeps on moving.
Visible crew/equipment: When the teacher is pairing up the students, a boom mic drops down from the top of the screen and is visible for about one second. (00:01:00)
Factual error: In the scene where T.J. Is explaining the formula to Mo that is written on the board, the right side of the equation (x-1)^2 is wrong. It should be x^2 - 2x + 1, not x^2 - 2x - 1 when expanded. Also, at the start of the scene with the formula, the coach who is teaching the class states he wrote it, and then it is assumed T.J. came up and finished solving the equation, but the writing is exactly the same. (00:08:15)
Book Smart - S2-E8
Visible crew/equipment: When Floyd and TJ are talking in the kitchen after the girls leave, a boom mike can be seen at the top of the screen.
Continuity mistake: When Louis returns to the house with the ice, he sees Mo with his hand on the girl's chest and has the ice over his shoulder. When the shot cuts, the bag has disappeared. (00:13:30)
Working Guy - S2-E2
Revealing mistake: When Yvette and Floyd are playing basketball, the guys come home and distract him. Yvette makes some impressive shots, and you can tell that it's a stunt double because the hair is totally different. Yvette's is big and puffy, and the double's is long and straight. (00:08:15 - 00:09:40)
Revealing mistake: A little oversight on the part of the producers. At the final scores that we are shown, Amy has $10,000, TJ has $9,800, and Travis has $2,400. This all adds up to $22,200. Even if they only answered $400 questions (which we can see that they don't), that's about 55 questions at best, only in the first half. That would run way longer, probably about three or four times as long, as any normal game show. And there's no mention of any other rules regarding the scores so there's no reason to think that there are bonus questions that could raise it that much.
Answer: It's reckless and irresponsible and it's not something that he does normally. But, it is something that Marcus would do.