I don't think he's referring to the new CBD medication that came out, I think the OP is referring to CBD via vaping, smoking, or other means such as CBD processed into foods/beverages/etc.
There is no such thing as pure CBD, there will always be some amount of THC however trace the amount. Medical grade CBD is not perfect. My previous neurologist had me try CBD, so I did.
I tried CBD twice both times medical grade although I don't know THC concentration. Here's the rub:
If you have schizophrenia or any other mental illness that can cause hallucinations, you WILL get high even with THC free CBD. I can't even imagine what would've happened to me if there were THC in my system after that. I probably would've wound up in the hospital.