There's Something About Paulie - S2-E16
Deliberate mistake: At the dealership, Lois pops the hood of the red car and shows there is no engine in the vehicle. She pulls out a paper that just has a drawing of an engine. Yet moments later, Peter is able to start the car and rev a nonexistent engine and drive it a couple of feet before the wheel falls off. (00:02:40)






Suggested correction: Quagmire considers the rest of them to be his best friends. He isn't drinking because they can't drink. He is complaining because since his friends can't drink - he won't drink, so he is still pissed.
It's still a plot hole considering Quagmire's age. I think the writers messed up big time.
You make a good point, but it's awkward to be that one person who is drinking while surrounded by people who can't. So, I understand the correction that was submitted above. Because his friends are not drinking, he now feels that he can't.
It's 100% a mistake. Quagmire simply would buy them alcohol the same way Brian did when they realized he could.
ctown28 ★