I think again, being doctors factored heavily into the willingness of others in the group to help.
As doctors, they are well acquainted either personally or by general anecdote with stories of doctors who made good judgement calls but were pilloried for the decisions later when parents died or suffered traumatic after effects, etc. They have to live daily with sometimes making split second decisions with impartial information.
My FIL suffered a mild heart attack about 13 years ago. When he was taken to the hospital, he was administered a dose of the TPA drug (I think it's a blood thinner) to alleviate the effects of the drug. However, for a small percentage of people with stroke history or a predisposition to stroke, a slight difference in medication dosage can trigger a catastrophic stroke. FIL had never had a stroke, but his mother had.
My FIL went from one day being set to be released to the next afternoon in surgery for a catastrophic stroke that left him severely brain-injured and physically impaired.
Somewhere a doctor has to live with the results of the dosage he prescribed. (we confirmed this with a cardiologist relative after all this happened.) I'm sure all doctors at some point and in varying degrees, come in contact with that aspect of being a physician--being unfairly at times blamed for decisions or even fairly blamed, whatever.
So I believe that the McCanns friends would be more sympathetic to helping cover up a "mistake" that resulted in the death of their child. They would see it as the McCanns suffering needlessly for what was a mistake in judgement and an accident. Why should they lose their other children if the authorities decided they were negligent? Why should they be faced with losing the reputations, careers, and possibly medical licenses? Any overdose for a doctor's child would be splattered across the tabloids. "Dr. Mum Doses Tot to Death."
That's why sometimes Kate looks so grief-stricken and despairing, she really is mourning her child. Other times she is able to talk to herself about how her child is now in a better place and would want the rest of the family to be happy. It's why she can say with such certainty, "Maddie knows we love her" when asked what she would say to her child.
http://news.sky.com/skynews/video/vi...-1279448,.html