In order to be convicted of your everyday first time DUI in California, under Vehicle Code section 23152 the prosecution must prove (beyond a reasonable doubt):
(a) It is unlawful for any person who is under the influence of any alcoholic beverage or drug, or under the combined influence of any alcoholic beverage and drug, to drive a vehicle; or
(b) It is unlawful for any person who has 0.08 percent or more, by weight, of alcohol in his or her blood to drive a vehicle.
The key components to a DUI in California is that the person actually drove, or moved, the vehicle no matter how slight, and that the person was under the influence and/or .08 or higher AT THE TIME OF DRIVING. What the level of BAC was at the time of the chemical test is important, but it does not mean that was the level of intoxication at the time of driving.