It might have seemed like an open-and-shut case when prosecutors charged a 62-year-old Coos County man with drunken driving.

An Oregon State Police trooper detained John Charles Hedgpeth under suspicion of driving his motorcycle while under the influence of intoxicants. When Hedgpeth took a breath test back at the station, his blood alcohol content registered a .09 percent. The legal limit for driving is .08 percent.

A strong case, right?

Coos County Circuit Judge Richard Barron thought so. The judge convicted Hedgpeth of driving under the influence of intoxicants in October 2014.

Thursday, however, the Oregon Court of Appeals reversed that conviction -- finding that there was a major hole in the prosecution’s case: An hour and 45 minutes had elapsed from the time Hedgpeth was stopped to the time police tested for his blood alcohol content.

The Appeals Court ruled that it’s possible that Hedgpeth was still legally sober when he was stopped -- but in the time he was in police custody, more liquor entered his bloodstream and raised his alcohol content to an illegal level. In other words, Hedgpeth could have slammed some drinks moments before he was stopped on March 21, 2014.

The court also said it’s possible that Hedgpeth’s blood alcohol content at the time of the stop was higher than .09 percent -- and the hour and 45 minutes gave his body time to burn off some of that alcohol.

The problem is that the prosecution didn’t present evidence to prove which theory was actually true, the Appeals Court said.

Hedgpeth’s defense attorney, Paul Burgett, told The Oregonian/OregonLive on Saturday that he’s not sure if an hour and 45 minutes is an exceptionally long amount of time to pass before administering a breath test. He said in some rural parts of the state the nearest breath-test device could be a considerable drive away.

Handheld devices that measure alcohol content by the side of the road are an option in some states, Burgett said.

“You get a reading right there,” Burgett said. But in Oregon, Burgett said the Legislature hasn’t approved those devices for police use.

It's also worth noting that prosecutors don't need a .08 percent test result to prove a defendant is guilty of DUII. Prosecutors can prove impairment in other ways -- such as through a police officer's observation that a defendant was swerving or failed sobriety tests.

But in Hedgpeth’s case, the trooper pulled him over not for bad driving, but because he wasn't wearing his helmet while operating his motorcycle.

What’s more, police gave Hedgpeth field sobriety tests, but the results weren’t entered into evidence for reasons that are unclear.

Hedgpeth was previously arrested for DUII in 2008 and pleaded guilty. But the charge was dismissed after he completed a diversion program that included treatment and listening to victims of drunken driving talk about their experiences.

Read the Appeals Court's majority and dissenting opinions here.

Two of 13 judges dissented. They were Steven Powers and Joel DeVore.

-- Aimee Green