From a recent issue of Science I obtained the following information, derived from experiments with laboratory mice:
Neurons devoted to alertness, memory and learning, possess an enzyme capable of rapidly inactivating ethanol, the common drinking alcohol. Mice made deficient in such enzyme suffer from alcohol intoxication manifestations at much lower alcohol levels.

From that information it is permissible to offer the following hypothesis.

1.- We have known that when ethanol enters the body, it is catabolized by an enzyme present in liver cells. Low levels of that enzyme result in higher blood and tissue alcohol levels.
2.- What has been discovered now is that when alcohol penetrates the neurons, it is catabolized by a second, different type of enzyme.

Therefore, measuring alcohol blood levels will provide a datum on the combined result of both ingestion and of thedisposal of alcohol. Yet the important information, namely how much of it is present at the neurons, is not gathered at all.

As a corollary, only very low blood alcohol concentrations can provide negative information, while the presence of 'significantly' high blood levels does not provide the positive information about neuronal intoxication!

If so, then in the absence of an immediate test for neuronal alcohol levels, only an immediate examination performed in a specialized laboratory --for testing alertness, memory and learning at standard alcohol ingestion doses-- will be capable of testifying to the significance of the blood alcohol levels present at the moment of sample withdrawal...

Should the driver perish in an accident, more significant than blood alcohol levels will be an intelligent analysis of the driver's overall behavior. High alcohol blood levels will pale against a history of responsible behavior in situations that demanded alertness, memory and immediate learning of road dangers.

If the reader is unwilling to accept this postulate as valid, let him explain. If he is willing, what would he opine about the responsibility of the person driving the car that crashed with Princes Dianne dying inside it?