I understand having this rule and I do not personally drink and dive. However, how do you enforce this rule if someone wants "just one beer" during a SI? Are you shore or boat diving?
Basically, I see the same way I see the "how deep can I go" newby question. No one is at 60 feet checking for AOW or Deep Diver certs. If you do it (going that deep) you are ultimately responsible for the consequences. Unless you somehow restrain a diver, how do you keep them out of the water, other than not inviting them next time?
I am not being sarcastic. I am curious how this is handled.