Police stop vehicle for erratic operation and officer suspects that driver and passenger switched seats before stop. Officer admits there was some confusion at the scene as to which person was actually driving and that his vantage point did not allow him to see if a switch occurred. Police select client as driver and arrest him for OUI following standard field sobriety tests. Breath test results are .33 BAC. Defense presents alleged passenger at trial to admit she was the actual driver and her therapist backs up her testimony, confirming woman sought treatment for stress caused by her failure to admit the truth at the scene. Not guilty verdict following jury trial.