Hotel Dick - S2-E3
Revealing mistake: Right at the beginning of the episode as the camera pans over to the doors of the movie theater you can see the actors playing the Solomons waiting for their cue to come bursting out of the doors as if they were running out of the theater.
Proud Dick - S2-E13
Revealing mistake: When Harry lands in the yard, you can tell he lands on a crash mat, as the grass beneath him shuffles. (00:01:15)
Other mistake: When Harry spits baby food on the baby (the camera lens in actuality) in retaliation for the baby spitting food on him and Tommy, Joseph Gordon-Levitt breaks character and laughs uncontrollably and looks at and gestures to off-screen crew members a couple times. (00:06:25)
Dick, Who's Coming to Dinner - S5-E6
Dick: Does anyone remember why we all decided to be white?
Harry: Oh, um, I went with white ‘cause I thought it'd be a little cooler in the summer.
Tommy: Well don't you remember, Dick? All the television signals that we picked up in outer space were filled with white people.
Sally: Oh, except for that, uh, that black nerd with the hiked-up pants and the oversized glasses. What was his name?
Tommy: Bryant Gumbel.
Sally: Right.
Trivia: Dick is never seen walking in this episode and is only in an upright position when he moves from the chair in the lounge room to the wheelchair in the opening scene. This is because John Lithgow hurt his ankle playing tennis, and the episode was written to allow him to be in a wheelchair for the entire episode.