Michael Forrest Behne says that he drank one glass of wine, then left his house to go to a nearby gas station. He called his mom while he was out to see if she needed anything from the grocery store, and then started to drive back home. A few minutes later, he was in a serious accident, smashing head-on into another car, and supposedly hitting the airbag hard enough that it caused him to temporarily lose consciousness.

After the crash, Behne’s blood alcohol content was measured at a staggering .325, which is more than four times the legal limit in the state of Ohio. According to WXYZ, Behne couldn’t believe it; he insists that he seriously just had a single glass of wine. His mother couldn’t figure it out, either, especially because he wasn’t slurring his words and didn’t sound drunk or disoriented when they spoke on the phone.

Behne ultimately took a plea deal, was charged with aggravated assault, and is serving a two-year prison sentence. His mom, though, wasn’t satisfied with that outcome, and she remained convinced that something had to be wrong with her son.

When she read about auto-brewery syndrome, a rare condition that causes sufferers’ intestines to turn carbohydrates into alcohol, she started to consider the possibility that her son’s own body was the reason why he was spending the next two years in jail. “What we do find with this illness is that he can walk around for days at a time at two, three, four times the legal [blood alcohol] limit and be completely unaware,” Betsy Behne said.

In an attempt to prove this theory, Behne’s blood alcohol levels were tested at periodic intervals, at times when he hadn’t been drinking, and when hadn’t even had access to alcohol. “[H]e was quarantined in a hospital room for over 24 hours and his blood levels were taken on a regular basis, and they fluctuated up and down starting at zero,” Scott Croswell, Behne’s attorney, told WXYZ. “The hospital knew that he had consumed no alcohol prior to the testing starting, and over periods of time his blood levels would spike. They would go up, they would go down, they would go up, they would go down, and frankly the numbers were somewhat dramatic."

Knowing what caused his insane BAC might be reassuring for Behne now, but it didn’t help him in court: The state of Ohio is less interested in how a defendant’s blood alcohol levels increase than it is with the fact that it was above the limit, period. His attorney believes that the judge was “sympathetic” to his client’s condition, but that didn’t stop him from sentencing Behne.

There is precedent for using auto-brewery syndrome as a legitimate defense to a DUI charge, though. In 2016, a 35-year-old Buffalo, New York woman was pulled over after she was seen “weaving all over,” driving a car with a flat tire that produced “a large amount of smoke and a noticeable smell of burning rubber.” Her speech was slurred, she failed a field sobriety test, and her blood alcohol level was a way-past-the-limit .33.

Her attorney ultimately contacted Dr. Barbara Cordell, a researcher who had previously studied, written about, and encountered the condition before. She referred the woman to another auto-brewery syndrome researcher, who was able to get the woman correctly diagnosed. (She also underwent a significant amount of testing under controlled conditions. On one occasion when she was being monitored by two nurses and a physician’s assistant, her blood alcohol content still reached 0.36—despite absolutely not having a drop of alcohol). The DUI charges were dropped.

Matthew Hogg, who has spent the better part of his life trying to cope with auto-brewery syndrome, said that the condition can be miserable to deal with. “If I were to eat a normal diet containing grains, fruits, and processed foods with added sugar, I would experience the symptoms I have described every day, but I've learned to adapt my diet to minimize the fermentation in my gut,” he told VICE. “Despite this, the underlying cause of the condition has not been successfully treated, so I still suffer chronic symptoms, including fatigue, aches and pains, exercise and stress intolerance, and cognitive dysfunction, just not the symptoms of an acute, severe hangover.”

In Behne’s case, he believes that his own symptoms could’ve been triggered by an antibiotic prescription he took in college, or because of the time he spent working in a local brewery’s lab. (Part of his job required him to test strains of yeast, to ensure that they were fit to be used in the brewing process.) He was put on a low-carbohydrate diet and prescribed a strong anti-fungal medication after his diagnosis, and the sentencing judge recommended that he should be “housed in a hospital or medical facility” so that he could continue to treat his condition.

That request was ignored. Behne is in gen-pop at the London Correctional Institution, and is eating whatever carbohydrates are served in the prison cafeteria. He says that he has suffered a few “flare ups” during his incarceration, but believes that those aggressive early treatments did help.