Yes. Both breath and blood tests can produce inaccurate readings under certain conditions. Breath tests rely on properly calibrated equipment, correct sampling technique, and the absence of interfering substances in the mouth. If calibration records are missing or the device was not maintained properly, readings may be unreliable. Blood tests require correct collection, labeling, storage, and laboratory handling; failures in any step of that process can produce questionable results. Challenging accuracy is common in DUI defense because many factors outside of alcohol consumption can affect results. Promptly obtaining records, medical history, and procedural documentation allows for a thorough review to determine whether inaccuracies are present and whether those inaccuracies can be used to challenge the weight or admissibility of the test evidence in court.