Another attorney, Tony Brooklier, told KNX-AM that the arrest was a "good faith mistake, that's all."
Stow was almost fatally beaten by two men outside the stadium after attending the March 31 season opener between the Giants and archrival Los Angeles Dodgers.
A paramedic and father of two, the 42-year-old Stow was transported from Los Angeles to San Francisco in May after being in a coma and in critical condition for months before doctors upgraded his condition to serious in June. (Update Friday: Stow's family is reporting on the web Friday that he was alert this morning and able to mouth his last name.)
Ramirez, a convicted felon, is in prison for a parole violation after police found a gun in the house where he was staying when he was arrested.
The case attracted broad national attention and exposed how the Dodgers had cut back on stadium security. Ramirez was arrested after his parole officer spotted tattoos on his neck that matched witness descriptions of Stow's attackers.
Detectives at the Los Angeles Police Department's northeast division handled the initial probe that led to Ramirez's arrest. After prosecutors declined to file a case against Ramirez, detectives at the LAPD's prestigious robbery-homicide division took the investigation over and started again from scratch.
Robbery homicide detectives re-interviewed all of the witnesses in the case, which initially was based purely on eyewitness statements that were not corroborated with forensic evidence.
Even though prosecutors never filed a case against Ramirez, Police Chief Charlie Beck repeatedly said he was confident Ramirez was the right suspect and that he had been the main aggressor in the attack.
A prominent defense lawyer said Ramirez could have a case against the police department for false arrest. At the least, he is owed an apology, attorney Mark Geragos said.
"I don't understand why the cops said they got their guy, they were so confident," Geragos said. "It's outrageous. They should have stopped shooting their mouths off and concentrated on the investigation."
A message left for Beck was not immediately returned.