Well, you can make this into a pretty long drawn out case, with a large court fee and then your friend would be convicted anyway if he was indeed provably drunk. It really doesn't matter in Illinois if you are a lawyer or a cop... these are folks whose word is taken as gospel... even when they are clearly lying and clearly violating ethics. And frankly I'd give them every opportunity to find any way to convict your friend if he was driving drunk... IN ILLINOIS it is dui for a reading of .8. If you must drink, don't drive.