The Nutty Deputy Mayor - S3-E14
Character mistake: When the fat man attempts to prove that large people are unable to use the futuristic stalls, he's trying to access the toilet while the stall is open. If it were closed, as Mike had demonstrated earlier, there would have been no problem. (00:06:00)
The Kidney's All Right - S3-E9
Character mistake: Arthur wants to donate his kidney to Derek. It is claimed that he must be a match since he has O negative blood, but blood type is not the only thing required for a kidney donor, there are several other factors that could very well disqualify his kidney for Derek.
