There's a reason that the law recognizes the sanctity of certain relationships, and refers to them as "privileged." It's essential that people are free to be honest with, for example, their spouses, or their lawyers, or their DOCTORS. These sorts of privileged communications can't be used against us by the government. If it was any other way, well, it just wouldn't work out in our collective best interest.

So, when this guy tells his doctor he drinks more than a 6-pack a day, and the doctor reports him to the state, and the state revokes his driver's license, we have witnessed a fundamental and unforgivable breach of trust. HIS DOCTOR RATTED HIM OUT! And some idiotic state law says it's OK!

This whole thing stinks on ice, and it's situations like this that merit the phrase "chilling effect." Yuck.
CNN - Man loses license after telling doctor about drinking