Cornealious “Mike” Anderson lived a normal life for 13 years following his 2000 conviction for armed robbery because Missouri officials forgot he was out on bail. He’s now in prison and suing for his freedom, but state officials say he’s not the victim of cruel and unusual treatment.

The Missouri Department of Corrections realized in July 2013 that Anderson, then slated for release, never served a 13-year sentence for helping rob a Burger King employee in 1999 due to an apparent clerical error. He was arrested and forced to begin the stretch.

Missouri Attorney General Chris Koster said Tuesday in a court filing that Anderson’s belated time behind bars is not cruel and unusual, as Anderson argues in a lawsuit.

“The United States Supreme Court has upheld much more severe sentences for much less serious crimes,” Koster wrote. “No precedent indicates Anderson’s circumstances or anything like them are cruel and unusual punishment.”

Patrick Megaro, Anderson’s attorney, says Koster “missed my point entirely.”

“I’m not saying a 13-year sentence is cruel and unusual,” he tells U.S. News. “I’m saying enforcement of a 13-year sentence 13 years later, making it a 26-year sentence, is cruel and unusual.”

Anderson was granted bail pending appeal following his initial conviction. After he exhausted his appeals, Anderson says, he waited for officials to give him a date to surrender and serve his sentence. That never happened.

In a last-ditch court challenge in 2002 – after his appeals were exhausted – Anderson provided his new address and said he was out on bail.

“The state consented to Mr. Anderson’s bail pending appeal, for them to turn around and say ‘we didn’t know’ is completely wrong,” Megaro says. “They take no responsibility for the fact that for 13 years the Missouri Department of Corrections had a file on Cornealious Anderson as a prisoner and nobody picked it up or even bothered to look at it until July 2013.”

During his decade of freedom Anderson married, fathered four children and became a churchgoing small-business man.

“These kids really, really miss their father. They’ve never known life without a father. Now all of a sudden dad’s been gone nine months,” Megaro says.

Anderson’s wife, who has tearfully lobbied for his freedom in TV interviews, is “struggling to survive,” he says, and is suffering emotional and financial stress.

“It’s fundamentally unfair and it’s fundamentally cruel because you, the state of Missouri screwed up, you allowed this man to be lulled into a false sense of security, into thinking that they dropped the whole matter, and allow him to build a life … then come in one day and just pull the rug out from under you and say, ‘the last 13 years, kiss it all goodbye … we’re going to ruin your life and your children’s lives,’ that’s the cruelty,” Megaro says.

In the Tuesday filing Koster advised Anderson to refile the case against the Department of Corrections seeking credit for time served.

“I don’t think that’s a legally viable option,” Megaro says. “The law is very clear, you don’t get credit for time served in jail when you’re out on bail.”

Megaro is looking for other alternatives, but says he may forge ahead with the case as-filed. He says he spoke with Koster Tuesday night and “did not get the impression he personally wants to see my client in prison,” but rather is obligated to argue the state’s position.

“The state has to do what the state has to do, and toe the party line, so to speak – and the party line is that the guilty must be punished, and that’s it and that’s all,” he says.

The Burger King employee who Anderson robbed with another man when he was 22 years old told the NPR program “This American Life” in February he hopes Anderson will be freed.

“He wasn't out robbing other people, doing this, that, and the other,” the victim, identified only as Dennis, told NPR. “He seemed to have gotten his life together. You've got to give the guy a little bit of slack. I mean, yeah, he screwed up when he was little. But the law dropped the ball. The law ought to drop it completely. They need to leave the man alone.”

Despite the novelty of the dispute, Megaro says “I sincerely hope it does not go to the U.S. Supreme Court because if we get to that point it would mean four or five years have gone by, and I don’t know if these folks can hold it together that long.”