that person is a person from whom the constable would (in the absence of any incapacity of that person and of any objection under section 9) be entitled under section 7 to require the provision of a specimen of blood for a laboratory test;

it appears to that constable that that person has been involved in an accident that constitutes or is comprised in the matter that is under investigation or the circumstances of that matter;

it appears to that constable that that person is or may be incapable (whether or not he has purported to do so) of giving a valid consent to the taking of a specimen of blood; and

it appears to that constable that that person’s incapacity is attributable to medical reasons.

shall not be made to a medical practitioner who for the time being has any responsibility (apart from the request) for the clinical care of the person concerned; and

to take a specimen of blood from the person concerned irrespective of whether that person consents; and

to provide the sample to a constable.

has been informed that it was taken; and

has been required by a constable to give his permission for a laboratory test of the specimen; and

has given his permission.