I agree, but I would discuss it with her/him first. Often a therapist will ask a teen a question like this to get them to look at the grown ups side of it, to put them in the other person's shoes. It can backfire but it can also make a huge difference in how that teen sees the adult authority figure.
So I would make sure all the sides of it before going off on someone who may have had an ulterior motive for asking them this type of question. They also may just think you're nuts and the root of all your kids problems...
My hubby has a mental issue and his therapist had been seeing him for some time after a suicide attempt about 30 years ago. After meeting hubby's mother for about 15 minutes he came in and told hubby "I completely understand you now. Your mom is crazy." I loved her like she was my own mother and didn't see this side of her but the therapist certainly was able to get hubby back on track much quicker after meeting hubby's mom.
So if they think your teen does not need the meds or he hates them so much he wants to stop taking them then the therapist may have simply been trying to get teen to see things from a different perspective. You won't know until you ask.
Everyone has a choice when it comes right down to it. My cousin had a kidney issue where they were misshapen and he had to go do dialysis a couple of times per week. He was in his early 20's when he decided he had enough and stopped going. He died a few days later due to not having dialysis. He chose a different choice than his family, his children, or his wife would have chosen but he did make a choice.
"Hi Doc XX, teen came home from his meeting with you on XXX and he said some things I would like to clarify with you. He said you told him he can choose to take his prescribed medications or not. Could you tell me why this discussion happened?"