I would say that the law should be such that, had he blown a 0.07 THREE HOURS AFTER THE ACCIDENT he should have been charged with DUI unless he could show via scientific test that his alcohol metabolism was so slow that he need not have consumed enough alcohol prior to the crash to elevate his BAC above 0.100.
Maybe you should read a little more about the fella that ELK posted. He makes the opposite case you just did, her name is sarah and she had a glass of wine with dinner and then finished another after her dinner, one more quick drink and she noticed the time and had to go.
Then she gets pulled over down the block and the time it takes to get to the cop shop and take the BAC level it is actually MORE than what it was when she was arrested.
Seems I made that case a while back in this thread didn't I?
The truth is there is no way to know all the factors that need to be known to figure such a thing. Thus there is no way to apply a law equally to all people. That I think is one of the factors that justifies .08.