What was the reason behind the legislature 's intention to prescribe such a detailed procedure in section 129A for the ascertainment of the alcoholic content of the blood of a person accused of an offence in connection with the consumption of an intoxicant ? Why did it make such a careful demarcation of functions between the registered medical practitioner before whom a person is first produced by entrusting to him only the duty of examining the body of the person and if so requested of collecting his blood "for being tested for determining the percentage of alcohol ", and the Chemical Examiner or the Assistant Chemical Examiner or any other officer appointed by the State Government in this behalf by entrusting to them only the duty of testing the blood? It appears reasonable to think that the real reason behind all this detailed provision was the legislature 's anxiety to ensure that the very special right created by section 66 (2) in favour of the prosecution for the proof of alcoholic content of the blood shifting the onus on the accused should not be availed of in a manner that might leave loopholes for either errors or unfair practices.