or could be
perhaps the police did first aid whilst waiting for an ambulence and took a load of clothes off to look for injuries etc. Then whilst still waiting for an ambulance and the patient getting cold they decided the easiest way to get some clothes on him again was to use a forensic suit they had in the back of the car, whilst still waiting for the ambulence! How long was it between accident and ambulence attending? The medics would want them in the ambulence PDQ hooked up to machines etc and ready to roll.
Still, can always complain to the IPCC
G