I am not Alcoholic!

As I sit in my office, on my birthday, with no work whatsoever to do... I remembered of something that happened some 2 years back when I was at home for a vacation.
I have this weird pain in my right abdomen, it's not actually a pain, kind of I feel something there.
Well so I went to see a doctor with my Dad. Unfortunately our Family doctor was not in town so we went to another one who is next to it. The one from my native village and everyone coming to town from my village supposedly goes to him. Has a big name and is retired, so hopefully experienced.
Well he checked me and said it can be anything so get an Ultra-sound done. And so we did, the report didn't say anything special, except in the remarks section it said "Fatty Liver". On the way out we met another doctor (a younger one) who said, its not a problem, it would go away on its own. So there we were going to see the doctor happily for a final report.
When the doctor saw the report, he asked if I any eating problems, as it shows I have high fat and sugar.
I don't know what my Dad was thinking, because he just jumped over my answer and said, I drink a lot of coke and coffee. Well he was right, I had a habit. So as the final verdict the doc gave me a medicine "Alcoliv" and said "You have to stop drinking; coffee". And I said, yeah I think I have to.
Later when I searched about Fatty Liver and Alcoliv, is when I realized what had happened. Fatty Liver is a common occurrence in people who are Alcoholic (and hence medicine is Alcoliv). It does happen to non-alcoholic persons also, specially when you are overweight and suffering from "laziness". Which was the case with me. I don't have a problem when people don't believe that I don't drink or smoke. It even doesn't bother me now when people say I don't look that sober (You know.. "dekh ke to nahi lagta!). It has happened so many times now.
But the point is, isn't a doctor supposed to ask all these before prescribing something? How can he just assume from my face. With all those experience he has, why was he shy about asking that, he might have thought I would anyway deny in front of my Dad.
It wasn't a problem in US though, I just filled the form saying I don't drink, and they didn't need to ask me again. The doc just said, "choose your gym."