Marijuana is a drug and like all drugs, it has side effects. A lot of Asians have an adverse reaction to alcohol that causes them to get very flushed and a few other symptoms. I worked with a guy who can't use anything with caffeine in it. He once drank something that had a small amount of caffeine and his reaction was rather intense, his heart was racing, his breathing was affected and he was shaking. He knew it would pass which it did.
Unless someone has some experience with it, it's best to introduce it at a low level.
As far as it causing death, I don't know of any drug that can't cause death, but given the long history of cannabis, I suspect it's pretty safe on that metric. Unless there is a level that's been determined to be deadly, it's quite irresponsible to say someone died from it. People die from drinking too much but it is rare that someone actually dies of alcohol poisoning. There are, however, levels of alcohol in the bloodstream that are known to be deadly.