There is no preventative law. It doesn't have to be life or death; police aircraft can move anyone as long as that method of transport is in the patient's best interests "...when no other means of transport is available [or suitable]" The threat to life bit is largely in relation to the discretion to ignore the usual performance/third party risk for landing sites. The "or suitable" bit is where Shytorque correctly assessed that in one case ground transport was in the patient's best interests, though I've lost count of the number of casevacs I've done where the old wartime "is your jouney really necessary" came to mind.
I can't comment on the helmet bit as I only saw the last 20 minutes.
The cabin doors bit.....perhaps a spot of the old Yerkes-Dodson....