MIAMI BEACH, Fla. -

Testimony continued Wednesday in the DUI trial of a former Miami Beach cop, accused of driving drunk on duty, and running over two people on the sand with his ATV.

Derick Kuilan kept his head down in court Wednesday morning, the same pose he's kept throughout this week-long trial. His posture was the exact opposite of his most infamous pose alongside a bachelorette party at the Clevelander in Miami Beach.

That was the night two years ago, when he took his police-issued ATV for a joyride, eventually running over two people on the sand.

Wednesday’s main question at hand was whether Kuilan was drunk that night. The defense is challenging two DUI test tubes that show different blood alcohol levels, 0.077 percent and 0.088 percent.

Prosecutors countered the blood-alcohol discrepancy with a simple explanation from a UM toxicologist.

"The more alcohol is exposed to air, the more it depreciates," said Dr. Lisa Reidt, the University of Miami’s toxicology lab director.

Kuilan's attorney, Evan Hoffman, is trying to convince the jury that this is an incident that should be in civil court, not criminal.

Six other defense witnesses sat on the stand Wednesday, including a first responder from the Miami Beach Fire Department. The defense is making quick work of this trial, and is expected to rest after it calls on one more witness.