"(a) he had consumed alcohol after he had ceased to drive ... and before he provided the specimen and (b) that had he not done so the proportion of alcohol ... would not have exceeded the prescribed limit."
"below the limits, specimens of blood and breath respectively."
"(i) the offence did not require the court to ascertain the intent of the accused at all - conviction followed after a scientific test which was intended to be exact as possible; (ii) in most cases such a test was exact or, to the extent that it was less than exact, the inexactness would work in favour of the accused; (iii) it was the accused himself who, by drinking after the event, defeated the aim of the legislature by doing something which made the scientific test potentially unreliable; and (iv) the relevant scientific evidence to set against the result ascertained from the specimen of breath or blood was all within the knowledge (or means of access) of the accused rather than the Crown."
"It would, of course, be possible to say that the burden on the defendant is an evidential one but that he would not discharge that evidential burden unless he produced evidence relating to the potentially relevant matters we have set out. In a case depending on scientific questions and expert evidence that would not, in our view, be right. Mr Turner, [that was counsel for the appellant in that case] for obvious reasons, did not advance any such argument and it would diminish the difference between a persuasive burden and an evidential burden to vanishing point."
"Were we correct in accordance with the law and on the evidence we heard in reaching our decision and acquitting the defendant?"