seems like the ad was superfluous. the doctor treating your friend's condition would be aware of new drugs relevant to your friend's condition. i go to a doctor because i don't know about medicine, i don't want to be educated on medicine from snake oil salesmen.
Conspicuously absent from your scenario is the way the doctor becomes aware of the new drug. How does that happen?
How does it seem like the ad was superfluous?
The ad triggered a series of events that helped my friend.
The doctor, for whatever reason, was not the primary motivation.