These links are not really germane, as far as I can see they add nothing to our understanding of the incident. Salt Water Aspiration Syndrome, whatever the cause, is a phenomena that shows up some hours after the dive, it does not result in diving fatalities.
It has been reported here on this site, where by the symptoms can get worse and worse over time in cases where a diver is doing daily repetitive dives,just like Donna was. I'm not saying this is the cause, but it is not impossible. Such as if a wave of symptoms hit her while underwater.
Symptoms include:
"Salt water aspiration syndrome is not a condition that makes itself known immediately.... A persistent cough may develop. Nausea and vomiting are also possible. In rare instances, salt water aspiration syndrome can later lead to adult respiratory distress syndrome, which can lead to respiratory failure."
It us definitely germane to this thread and Salt Water Aspiration Syndrome should not be discounted as a possible contributing factor, as in dismissed out of hand.