The Intoxylizer 5000 breath machine that the police use may be prone to user error. For a variety of complicated medical reasons, the machine assumes that you have the “average” physiology. You don’t. We are all different and we all digest and burn off alcohol differently. By the time the police ask you to take a breath test, you are no longer in the same condition that you were while driving. Depending on when and how much you had to drink, your BAC may be higher or lower than it was when you were actually driving. At best, the Intoxilyzer 5000 provides a rough estimate of your BAC.
It is important to know what equipment was used during a breath test. Your DUI/DWI lawyer will obtain this information during the course of the case.