Really? What damage has been done? I re-read the original post, and I didn't see anything about bent metal, dead people, or anyone getting maimed. It seems to me that no damage has been done yet. But, if you do what you want to do, a lot of damage will be done. The company will get a huge black eye in the view of the public, the captain will lose his career, he'll probably never get help for his problem, and even worse, he'll probably just slip further into alcoholism because he's now lost his career and will cling to the bottle even harder as he slips into depression. Your way causes incredible amounts of harm to a lot of people. Him calling in sick harms no one.
What you fail to understand is that the company would cringe at your answer just as much as I do. A pilot being pulled from the cockpit for having alcohol in his system is a PR nightmare, and the airlines hate it. Their company name is going to be on CNN, in the newspapers, and on the local news, and not in a good way. Bookings will reduce for a short time, if only by a tiny bit. The company will have to spend around $50,000 to fight the arbitration when the pilot grieves the termination of his employment. The list goes on. The answers that others have given here are what the company wants to hear. They want you to get him off the trip without creating a public ruckus. They want you to refer him to HIMS so he can get some help and come back as a loyal employee (industry-wide, HIMS graduates have proven to be some of the best employees). They do not want you to create a scene by putting them in a situation where they have to get the authorities involved.