"'...if a driver is adversely affected by drink, this fact is a circumstance relevant to the issue whether he was driving dangerously. Evidence to this effect is of probative value and is admissible in law. In the application of this principle two further points should be noticed. In the first place, the mere fact that the driver had had drink is not of itself relevance: in order to render evidence as to the drink taken by the driver admissible, such evidence must tend to show that the amount of drink taken was such as would adversely affect a driver or, alternatively, that the driver was in fact adversely affected. Secondly, there remains in the court an overriding discretion to exclude such evidence if, in the opinion of the Court its prejudicial effect outweighs its probative value.'" 22. "
"Cocaine is a Class A controlled drug. The forensic science service can detect unchanged cocaine in blood samples typically for 3 to 6 hours after use depending on the dose and the method of drug administration. Cocaine is a drug of addiction and is abused by either inhalation through the nose or smoking form of cocaine known as crack. Cocaine is rapidly and extensively metabolised in the human body and therefore the presence of unchanged cocaine in the blood sample demonstrates the recent use of this drug by him. Cocaine is a powerful stimulant drug that can produce hyperactive and feelings of euphoria, selfconfidence and strength. Larger doses induce delusions, paranoia, acute anxiety and a tendency to be violent or aggressive. Persons under the influence of cocaine may experienced blurred vision and demonstrate increased risk taking behaviour. The stimulant effects of cocaine typically last for half to 1 hour after which there may be a strong compulsion to take more of the drug. After the stimulant effects of the drug have worn off the user may exhibit signs of irritability and drowsiness. Cocaine may therefore adversely affect a person's ability to properly drive a mechanically propelled vehicle."
"Well that's impossible that's absolutely impossible. Is it? Yes, I wouldn't take cocaine."
"As far as cocaine was concerned, he was challenged by Mr Shay and he said: 'I cannot explain why there were traces of cocaine found in my blood. At first I denied to the police ever taking cocaine because it was not particularly clever thing to do. I agree I initially lied to the police but then I told the truth and later admitted it.' He said he had taken cocaine maybe five or six times in his life, it just makes him talkative and erases his fears; he snorted it. He has never taken cocaine shortly before driving a car. He would never have done so. He cannot imagine, he told you, that it would make any difference when driving a car but he wouldn't want to risk it. 'I should imagine' he said 'it would depend on the quantity taken', but it has never happened to him so he doesn't know. He wouldn't have taken cocaine that night because he was working the next morning, and the reason he would not have done so, he told you, is because it would have affected his faculties."