My wife is in school to become a pharmacist and after talking to her and a few other people I know in the medical profession you kinda realize how much regular doctors don't know about the drugs they prescribe. Not saying that would have changed what happened with your friend sometimes nobody can predict what will happen, but I'm going to go on this quick rant anyway.
From what she told me doctors for the most part are required to take one or two semesters on pharmaceuticals, and that's it. Compare that to your average pharmacist where that's all they do for 4+ years (pharmacists are required to have a doctorate now). Yet my wife has told me of patients/customers (she worked as an intern with CVS for several years) who absolutely refuse to listen to the pharmacist when they make a recommendation.
Apparently just in the last 5-10 years pharmacists have started taking on a clinical role; going on rounds with regular doctors in hospitals to make recommendations on what drugs the patient should be on, making sure there's nothing that's going to cause complications, etc.
TL;DR - If your pharmacist has a recommendation for you, listen to what they're saying. Drugs and their effects are basically the only thing they studied for 4+ years. And they keep up with developments in the industry beyond what the pharmaceutical companies tell them at fancy dinners. Your doctor meets with drug reps and does his best, but he's got a lot of other stuff to focus on.