WEST PALM BEACH (CBSMiami) – Closing arguments will begin Friday morning in the DUI manslaughter trial of Wellington polo magnate John Goodman.

The trial began Thursday morning with the cross-examination of the final witness, a crash-reconstruction expert.

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Thomas Livernois testified for prosecutors that he doesn’t believe Goodman’s Bentley malfunction by suddenly accelerating. His testimony contradicts that of a defense expert who said one of the Bentley’s two throttles malfunction, which made the car surge forward.

When cross-examination was done, the prosecution and defense moved into closing arguments.

“The defendant had in his system at the time of the crash between .20 and .23 blood alcohol and a therapeutic amount of hydrocodone,” prosecutor Sherri Collins said during her closing.

Goodman’s attorneys said there’s nothing to back that up and that investigators ignored evidence. In fact, attorney Roy Black said prosecutor Ellen Roberts “put the screws” to a bartender, one of the key witnesses, trying to get testimony that would fit her case.

“She was intimidated,” said defense attorney Roy Black. “She was threatened. She said she got nervous, she wanted to vomit, she said her hands were shaken.

Goodman is charged in connection with a February 2010 crash that killed 23-year-old Scott Wilson. Prosecutors claim Goodman was drunk when his Bentley slammed into Wilson’s car. The force of the crash pushed the car into the canal where Wilson drowned.

Investigators said Goodman left the scene and waited nearly one hour before calling 911.

Goodman’s defense team argued he didn’t realize he had hit the vehicle and then left the scene to get treatment for his injuries.

Wednesday, Goodman took the stand in his own defense. He testified for nearly two and a half hours before the defense rested its case.

“That night at the Players Club,” defense attorney Roy Black asked Goodman, “did you ever have a drink called an Irish Car Bomb?” Goodman answered, “Absolutely not.”

Black continued, “When you got into that car were you either drunk, impaired or intoxicated?”

“Absolutely not,” Goodman said.

Prosecutors claim Goodman was driving under the influence when he crashed into Wilson. A blood sample taken nearly three hours after the crash showed Goodman had a blood alcohol level of .17; more than twice the legal limit.

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Goodman’s attorney tried to counter the DUI accusation with another theory. His expert testified that the millionaire left the scene because he may have suffered a concussion and did not behave as you’d expect someone to if they were just in an accident.

“There could be difficulty with reactions, walking like you’re drunk,” said defense neuropsychologist Dr. Richard Hamilton. “It can be visual problems.”

Goodman admitted on the stand that he had four drinks over the course of the evening.

Goodman said the last thing he remembered before the accident was that the brakes seemed odd.

“So I continued to apply the brakes and I slowed before the stop sign, well before the stop sign,” Goodman said. “I took my foot off the brake and that’s the last thing I remember.”

Goodman told the jury that after the crash, he passed out. When he came to, he said he was disoriented and didn’t initially realize he hit anyone, because Wilson’s car was submerged in the canal.

Goodman said he took off walking, looking for a phone. He said he ended up in an office in this barn, known as “a man-cave with a TV and bar. He said he had a few drinks to kill the pain of his injuries and that’s why he failed a blood alcohol test.

“It would take 11-14 ounces of alcohol to get to that level,” pointed out prosecutor Ellen Roberts.

“Ok,” replied Goodman.

“That’s 11-14 one ounce shots,” Roberts continued. “Is that how much you drank?”

“Must have been,” Goodman said.

Goodman told the jury he drank in the “man-cave” and then hiked through a field to a nearby trailer where he first called his girlfriend and then called 911. On the 911 tape, Goodman sounded disoriented, continually asking if everyone was alright.

He said that it was during that call that he got scared, realizing the wreck was worse than he knew.

Goodman’s case garnered international attention when he adopted his adult girlfriend as his daughter to protect his assets from any civil lawsuits.

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If convicted, Goodman faces up to 30 years in prison.