Brandon Adams was accused of kidnapping the star last June (10) after he and his friends offered to help the actor change a flat tyre on his car.
The 27 year old has accepted a plea deal, admitting to lesser charges of felony false imprisonment and a misdemeanour charge of vehicle theft.
Adams was sentenced to 16 months behind bars but he had already served nine months and was given credit for double that time.
Former Party of Five star London admits he felt relieved by the outcome after his own mum and brother questioned the validity of his story, citing previous substance abuse.
London told the Palm Springs Desert Sun after the hearing, "It's vindication in a way. It's proof that I've been telling the truth the whole time. An innocent person doesn't plead guilty."
But the actor admits the case is not fully resolved, insisting Adams was not the member of the alleged kidnapping team who wielded the gun.
He adds, "We've never claimed that Brandon Adams was the one that put the gun to my head. The gunman is still out there."