A standard 'disclaimer' has virtually no legal validity (in hospital or anywhere else) since a name scribbled on a piece of paper does not tell you anything about 'capacity'. A court would need to know if a patient was able to retain the information about the treatment being offered (transfer to hospital in an ambulance for a medical examination). And if that person was able to weigh up the pros/cons - risks/benefits of what was being proposed, in order to arrive at a meaningful decision. Needless to say 'capacity' is impossible to demonstrate in a drunk with a head injury - how does anyone unpick the effects of the sauce vs the possible effects of raised intracraniel pressure (from a subdural, say). Of course alcoholics are known to be more at risk of repeated head injury and coagulopthy, increasing their risk of adverse outcomes, such as a brain injury requiring neurosurgical intervention. Doctors are authorised to treat patients, against their wishes sometimes, if the patient lacks capacity and treatment refusal is likely to endanger their life - as far as I know, no doctor has ever been disciplined for it (through the courts or GMC) since the doctor is simply acting in the 'best interest' of the patient. I'm slightly suprised that ambulance crews seem slightly less certain of their legal position, nor does there seem to be a standard operating procedure in cases where a patient may be combatative due to the effects of an expanding intracranial lesion (exacerbated by alcohol, of course).