Other mistake: A bank wouldn't lock someone in the vault all night. Employees make sure customers have left before locking up for the day.
Other mistake: Joe salutes Quagmire's Dad. His legs are paralyzed, yet he uses them to push himself backward in his wheelchair.
Road to the Multiverse - S8-E1
Other mistake: In every universe - except for the double-headed universe - Brian and Stewie travel to, they (seem to) replace the version of themselves that universe already has of them, but then in the Dog universe they have a separate version of themselves that they continuously interact with.





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 ★