To argue that the guy might have been legal elsewhere, or on some other day, doesn't hold water. Try driving down the M1 at 120mph.... and then explain to the traffic cop that it's legal in Germany.. If you're caught driving over the limit try explaining that it was perfectly legal 50 years ago.
Sure, I can recall drinking with pilots until 3am when they've been flying at 7.... I've seen a captain "walked" across the tarmac with an F/O under one arm and a steward under the other and I've visited flight decks which stank pubs.... but that was half a lifetime ago and things have changed - for much the better for us all. Hopefully we are all more safety concious now?
To the pilots who see no problem.... the guy was breaking the law. Full stop. If you argue that it was OK do you blatantly disregard other rules applicable to your position? When it's low vis do you gaily descend below DH? Aviation is strictly controlled by rules which apply to pilots, engineers, controllers, etc. The purpose of those rules is to enhance safety and prevent people from being killed and as professionals we should strive to follow them.
Alcohol means nothing to me - I could go for a year without a drop. For those who can't then I feel very, very sorry for you but implore you to consider those in the seats behind you before you break the rules.... (At my last but one medical before I retired AME poked around and said: "You're a controller, right?" When I agreed he said "I can tell from your liver - in most pilot's of your age their livers are down to their knees". Sad, eh?