I don’t assume the doctors made a mistake. Supposedly there is more information regarding what went wrong that the parents are blocking (thru not signing a HIPA waiver) which is really annoying the hospital who is left unable to defend themselves. I wouldn’t assume the hospital didn’t err, but I will say with certainty that it is not so simple to understand from the outside.
And regarding responsiveness, if there is no blood flowing to the brain, that is more telling than the movement of limbs.
I do wonder, however, if anyone knows legitimate stories of people who were declared brain dead (not coma) and recovered.