Well... There are persons that can takes as many bottles of alcohol and no matter the quantity they take, it will have no effect on them.
Yes it true that some people are chronic addicts who can easily control any volume of alcohol they consumed along the line at a time can walk and work perfectly fine without anyone noticing it. Although initially I didn't know he was only monitoring his trade with the smartphone, while I thought he was trading, I tried confirming from him the next time we met again and he said wasn't really deep into trading that very day he was monitoring rather.