Continuity mistake: When Lois goes outside to meet Hal at the clothesline, she leaves the door open. In a few shots during their conversation, the door is closed in the background. (00:06:20)
Continuity mistake: In the scene where the grandma is talking at the table with Reese and Malcolm, notice the bottle on the table next the the grandma, between takes the cork from the bottle goes from being on top of the bottle to next to the bottle, it changes in almost every different shot.
Revealing mistake: When Kristen starts taking her helmet off you can see her hair is actually a wig.
Other mistake: Lois wins the truck, which is never seen again.
Suggested correction: Just because we're not told what happened to the truck doesn't mean a mistake occurred. There's a number of valid reason we don't see it again (especially when only 3 more episodes were produced in the series).