Lying is a lie, nonsense, fiction.
Watching how you can teach a patient a lie, you can both say a doctor is lying or not.
If at the same time he does not violate the oath of the hepocracy and it will benefit the patient, then it can be considered not a lie.
And as an ordinary person - the doctor is lying like all of us ...
That is what we have being saying it depends on the health conditions of the patients for doctor to tell him not to smoke or drink but even the doctor is also supposed to uphold what he teaches and practice because his lifestyle also reflect on his Job.