Other mistake: Al is running the water down the rabbit hole. Bud says the ground isn't even wet and asks where the water is going. A few seconds later Marcy is walking through the yard squishing on the ground because it's flooded.
Other mistake: Bud calls a late night sex hot line which is a 1 900 number yet he only pushes 6 digits on the phone.
Oldies but Young 'Uns - S5-E17
Other mistake: Just before Charlie and his son leave Peg says "Charlie, my watch". Implying that he took it off her wrist. Yet during the whole scene she didn't have a watch on her wrist. It appears in his hand out of nowhere.
Answer: It was one of the hoses connected to the engine, nothing specific, but to indicate that Al tampered with the vehicle.