First of all, NEVER agree to a blood test without speaking to your lawyer! I don't drink, but I do occasionally drive after taking hydro (we're talking only 5mg here). I wouldn't fight with the cops either, that wasn't too smart (but I'm sure your friend realizes that now). If he had just kept quiet, the field test would have shown he was sober and he would have been on his way (oh and believe me, I know how difficult it is to keep your mouth shut when you feel you're being accused unfairly!).