I don't think Ray was a suicide
Jerry Brainium, IronMan author and Mentzer's friend mentioned that while it was officially listed as some sort of cardiac malfunction, Mentzer also had lethal levels of some sort of drug.
Edit: here's a c/p of the post from Dave Drapers forum:
"I viewed the offical autopsy report of both Mike and Ray Mentzer, who were long time friends of mine. Mike's offical cause of death was athersclorotic heart disease, and the same for Ray. Yet the toxilogical report listed lethal doses of pain-killing drugs and antidepressants in both men. I asked the coroner who did the autopsy about this apparant discrepancy, and he said that it was difficult to determine which came first, the heart attacks or the overdose. He also said the drugs may have triggered the heart attacks." .