Other mistake: When Mac shows the news crew how he can call up a lot of info on his computer, the video game Super Mario Bros. appears on the screen but, the music that is playing is from the video game Super Mario Bros 2.
Other mistake: It is daylight outside when Cliff and Clair are talking, but when he turns the lights off to try on his light-up Father's Day gifts, it gets pitch black in the room.
Funeral at Fifty-Mile - S1-E22
Other mistake: It's a clear day not a stormy night as it should be when showing the barn in the flashback. Look closely and you can see a clear sky through the barn walls cracks.
A Case of Sour Grapes - S1-E14
Other mistake: There is a sour bottle of wine that Jack and EZ taste in the kitchen - Jack throws the bottle in the sink and breaks it before Vicky and Mr. Bradford enter the kitchen and have a chance to taste it. There would be a strong sour smell all over the kitchen, but no-one in the room noticed any bad smell after the bottle of wine breaking.