I read this morning that it's quite possible that he didn't take all of these types of pills on the same day - could have been days apart. People don't realize that these things happen all too often, complete accidents, because most aren't aware of the dangers.
![distress](images/smilies/distress.gif)
The brain simply forgets to tell you to breathe, or to roll over if you're face down in a pillow. The nervous system is too depressed to do its job.