During the fermentation process yeasts always produce carbon dioxide gas as well as alcohol. It is a result of the chemical conversion from carbohydrates (sugar or starch) to ethanol, and it is an incomplete conversion with carbon dioxide produced in various amounts depending on the conditions. If this person really had a yeast factory in his gut strong enough to produce intoxication I would certainly suspect that he had some really serious gas
and other colic like problems too. With such a condition you won't be able to fly anyway
He may even be hypoxic also as carbon dioxide can go through the gut wall.