On the other hand, both the medical system and medical professionals have to deal with all of the above. Every day. And, being human, most of them are quick to reach judgements which amount to "he's lying, it's his own fault, give my attention to patients who deserve it".
But on the third hand, why in nearly 10 years couldn't he have found some creative proof that he wasn't a drinker? Say, a locked treatment facility for alcoholics, where he'd still have a high blood alcohol level after several days without physical access to drinks. Or lab cultures of his gut microbes showing high levels of the responsible organisms. ABS has been known since the mid 1900's, and isn't that hard to find on the web - https://en.wikipedia.org/wiki/Auto-brewery_syndrome