Idk, I heard a police detective (retired) speculate that it was carbon monoxide. I guess the first thing that people feel with CO is a terrible headache. He thinks that one spouse, Gene, was overcome and fell down, meanwhile the wife went to get headache meds from the bathroom, and was overcome and fainted, then succumb to CO poisoning. Or it happened the other way around. The fact that one dog is deceased, he was the only dog in a crate.
It's a fascinating story b/c they're famous. Also, it's highly unusual for three to die (2 people + 1 dog) all at once.
But another police detective said, "You can't tell me that in a 3 million dollar home, they don't have CO detectors." I find it hard to believe they wouldn't have CO detectors in such an expensive home as well.