I just wanted to throw out a new (alcohol only) scenario, after we learned from Fox4/Inside Edition that there are chairs in the backyard. I had mentioned that the existence of chairs would make for new scenarios.
Three men go into the backyard, sitting in chairs near each other (one of the porch chairs is used). One man nods off almost immediately, so now it's only 2 men, passing a bottle back and forth or drinking from separate drinks. These two regard the first guy as "sleeping" and figure they'll wake him up when they decide to leave. Second guy nods off, third guy is too drunk to realize that and about to pass out himself. IOW, all three were at the. black-out point of drinking and all three were unable to understand or feel the cold (due to the alcohol).
Someone on this thread mentioned a photographer project (star photos?) wherein they lay down on plastic on cold ground and fell asleep (no alcohol) even though that wasn't the plan. Woke up hypothermic and disoriented.
I'm not saying this happened, just that it's possible. I agree that LE would have the ability to test for various drugs at the scene. I know it sounds far out there, but theoretically it's possible and, I suppose, statistically not exactly zero probability. Louise Ehrdrich has written a short story about an accidental (alcohol-related) hypothermia death - these happen in the Dakotas with some frequency. But there's more than simply trying to say it does happen. There are reasons why people who are drinking are more likely to die of hypothermia:
Alcohol is a dominant cause of death in urban hypothermia. Drinking alcohol gives a pleasant feeling of warmth. However, experimental studies on humans during relatively short exposure to moderate cold have given inconsistent results concerning heat balance. Longer exposure to colder...
pubmed.ncbi.nlm.nih.gov
We do not know that they all died within seconds or minutes of each other. If it's true that they went out there at approximately 2 am, it was cold all night and they could have died within a window of hours of each other. They could have been past the shivering phase of hypothermia (masked by alcohol) very quickly. A resting person with ethanol on board would become hypothermic more quickly than a sober, moving person. Without a tent or sleeping bag, hypothermia can set in while sleeping or unconscious in 50F, it was 30-32F until mid-morning in Kansas City (roughly speaking). Extremities/tips of nose/fingers would start going numb and start to freeze after about 30 minutes - less, if there was even a small breeze (it was calm to 5 mph winds that night, IIRC). So, after an hour, the body temperature would start to drop - and continue to drop until the person got up and sought warmth.
Anyway, that's the scenario I was thinking about when wanting to know whether chairs or not. A comfortable place to sit and stretch out and continue the "festivities" may have resulted in hypothermia even before unconsciousness, which causes mental confusion and even an early paradoxical feeling of warmth (and alcohol adds to this by giving the illusion of warmth as well).
THis article from the NYT (using mortality stats from the US database) says that 80% of hypothermia deaths include alcohol or being without shelter or both as a component:
www.nytimes.com
These three men were without shelter in the yard, and could have been using alcohol.
IMO.