Police respond to scene of single car accident with both air bags deployed and two occupants nearby, both bleeding from impact. Client admits to two beers and a margarita and is arrested following field sobriety tests. Defense excludes post arrest breath test evidence of .14 BAC because government does not have an expert witness to relate breath test results to blood alcohol level at time of driving. Blood found on driver’s side airbags could be attributed to either occupant leading to question as to who has actual driver of vehicle. Not guilty verdict following trial.