Has anybody ever heard of somebody passing out because of marijuana?

Me and my dad were talking about one time when he passed out a few years ago when I was eleven. He was just standing up straight and fell face first on the floor and lay there passed out for like 10 or 20 seconds. then it happened twice again with the next 20 minutes. We were talking about why it was recently because he had a stroke and they were talking to him about it, and he said he thinks it was drug induced, and I assumed he was talking about weed because he smokes every night so it seemed casual. But he has been smoking for 30 odd years and isn't a light weight and I have never heard of people passing out from it.