Other mistake: The guys all go water skiing, towing the boat behind Peter's car. After Quagmire gets his penis bitten off the scene cuts to the hospital parking lot. Quagmire's car is parked next to Peter's. There would be no reason to go home and get his car instead of going directly to the hospital. (00:07:15)
Other mistake: When Stewie and Brian are riding on the train, Stewie tells Brian, "It's nice that the locals act as their own train crossings." They are seated on the left side of the train and looking out their window at this time. As the train passes, we can see the only person standing there is on the right side of the train. Neither Stewie or Brian could have seen him from the direction they were looking. (00:14:10)





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 ★