Always interesting to get a glimpse into the mindset of people. The problem is not that the Captain showed up under the influence of alcohol, the problem is that I said something. Ok then.
All I would do is call into the company and report that I am not going to fly with this Captain. If asked, I would give my reasons. It then falls to the company to decide what to do. If it truly is an honest mistake, then no harm done (although I suspect the Captain will never invite to go fishing with him). If the Captain is under the influence, then he has earned whatever action is taken. As for mitigating circumstances, that is for the Captain, the company, and the FAA to sort out.
The problem is that, in the scenario described, the Captain has already had contact with any number of people who are capable of making a similar judgement (security, airport personnel, ops agents, etc). Any one of those people could have made a call to airport police or the company. Further, he has already dutied on, thus reporting himself as fit for duty. So he's already "on the record" (as it were).
I suppose I could still advise him to call in sick, and probably would. And as I have already said, had this situation occured in the hotel lobby, the airport van, or anyplace where it is just he and I involved, I would do exactly that. But now he's on duty, and at the airplane. He's had contact with any number of other people, and I have to assume the airport police are running down the jetway right now. He's jeopardized himself, me, the rest of the crew, the ground agents, and of course, the passengers. It's a bit too late to walk that back. The proper thing for me to do is to protect myself by calling it in, and protect everyone else by making sure that he does not do anything more stupid like trying to operate the airplane in any fashion. I don't even want him throwing a switch. In case you haven't heard, alcohol impairs judgement (pass it on).
If that makes me a "company man," I'm ok with that, because it is the company that signs my paycheck. It's the Captain who is jeopardizing it.