Let me tell you now that I don't think that the science used by medical examiners is all that accurate. I have personal knowledge of inaccurate findings. Without going into to much detail - someone I know died of a gunshot wound - automatic inquest. The coroner/ME found that the person had small amounts of marijuana in their system and had probably last smoked it about three weeks prior - trace amounts of cocaine were found but nothing in nasal passages - so they concluded he had not snorted it in the hours prior to his death. Let's just say I know for a fact that these findings were totally wrong. So I'm left to believe that this is an inexact science.
It's obvious just by listening to Perper that this is an inexact science. 90% of what he said is hearsay. She felt this way, she didn't feel that way, she went here, she didn't go there. HTH does he know what she felt or what she did or didn't do.