As far as I know no one has died, either directly or indirectly, from smoking pot, unless there may have been a chronic condition. The professionals you listed above only rely on what the Govt. feeds them, in this case in Canada. I have done quite a bit of studying cannabis.
My opinion, somewhat backed up by these "professionals", is that anyone under 18 to 20 years old shoud not smoke pot, the brain is still developing and you don't want to disturb that process. And the benefits far out weigh the risks, the risks being; lung damage by ingesting smoke (to counter that, use a vaporizer, no smoke involved) and most recently, there is a possible risk of testicular cancer among men and Nancy Pelosi! The benefits include relief to those that suffer from gloucoma, provides pain relief to chemo patients, and anyone who needs to eat more to stay alive (the scientific term is "The Munchies". The article did not give any tangible statistics, just statements. I'll admit that I know nothing about the effects with psychosis. In that regard, I would venture that there a lot of drugs and medicines that should be avoided.
I have NEVER heard or read anything about death caused by weed... And that would make the headlines!
On the contrary, it has saved the life of 2 of my best friends, one with aids and the other with a massive chemotherapy.
So I had a stroke that was seen on my MRI by more than 1 physician and the only thing that could explain it was smoking weed. I don't smoke cigarettes and haven't done speed or any other drugs for 28+ yrs. I have no other signs of cardiovascular disease as had thousands of dollars of testing done. The only thing I had done that day is smoked about 3 joints, my normal daily intake varies from none to about that much, so explain that one to me. Now I've experimented and every time I smoke I feel a constriction in my left neck and face so no more for this chick. Just sharing.