Character mistake: When Sally asks if Rob would give his party guests malaria, Rob responds later on with, "Oh, Roe, I would never suspect you!" Roe was Rosemarie's nickname on set.
I Do Not Choose to Run - S5-E16
Character mistake: Rob tells his council men that "Richie loves helping his mom in the kitchen" yet every time she's in the kitchen cooking or doing anything of the sort. Richie is nowhere to be seen. The only times Richie is near the counter is when he's hiding under the counter, or drying his hands like the rest of the family.
Character mistake: Rob is telling Laura about how Buddy and Sally work he says "Sally is the only one who can type with all her fingers." Yet Rob can type with all his fingers and doesn't say anything about that.