Graham Spanier, who served as the school's president for 16 years, has not been charged with any crime, but an independent investigation conducted by former FBI director Louis Freeh accused Spanier of failing to alert authorities that Sandusky sexually assaulted a boy in a locker-room shower.
Spanier has insisted that was never aware of the allegations that Sandusky had sexually molested a boy.
Two other school officials have been charged with perjury and failure to report abuse, and authorities have indicated the investigation is continuing, leaving a legal cloud over Spanier.
The scandal ended Spanier's tenure as the school's president and the Freeh Report damaged his reputation by faulting Spanier for failing to stop a "child sexual predator harming children for over a decade."
Tim Lewis, a former federal prosecutor and ex-federal judge who reviewed the Freeh report's findings on Spanier's behalf, called the investigation's findings a "myth" and a "blundering and indefensible indictment" that would never hold up in court.
Lewis said the report was filled with "glaring oversights, indefensible exclusions... [and leapt] to conclusions with no basis except the biased opinion of the author."
"The irony is that while this report attempts to portray Dr. Spanier as having engaged in a conspiracy to conceal information, a closer inspection confirms that if anyone is guilty of concealment it isn't Dr. Spanier; it is Judge Freeh," Lewis said.
Lewis acknowledged that it was unusual for one former federal judge to criticize another former federal judge and added, "It pains me to say this," referring to scathing criticism of Freeh's report.
A spokesperson for Freeh told ABC News, "We stand by our report."
Lewis insisted that had Spanier, a victim of child abuse himself and an expert family therapist, been appraised of Sandusky's crimes he would have reported them.
Instead Penn State officials told Spanier that Sandusky had only engaged in "horseplay" with a boy in the school's showers in 2001. The boy would later be identified as Victim 2, one of 10 victims police would later learn Sandusky had molested.
In July, Sandusky was convicted on 45 counts of abuse against 10 boys.
"'Horseplay' was referred to over and over again, but never with any sexual connotation or suggestion of abuse," Lewis said.
Those comments echo Spanier's previous denouncements of the Freeh report.
"Had I known then what we now know about Jerry Sandusky ? I would have strongly and immediately intervened," Spanier wrote in a July 23 letter to the Penn State board of trustees. "Never would I stand by for a moment to allow a child predator to hurt children."
Two of Spanier's former colleagues, Athletic Director Tim Curley and retired Vice President Gary Schultz, face trial for perjury and failure to report abuse.
The charges stem from allegations that Curley, Schultz and Spanier never told authorities about the 2001 shower incident.
After the scandal broke, Spanier, who was president of the university from 1995 to 2011, was demoted to a professorship.
According to documents, the Freeh report and testimony at Sandusky's trial, Spanier learned in February 2001 that assistant coach Mike McQueary witnessed an incident between Sandusky and the boy later identified as Victim 2. During the trial, McQueary suggested that the incident was a rape of the boy.
Spanier, however, insists that he was never told the seriousness of the attack on Victim 2.
But the Freeh Report concluded that Spanier and his colleagues understood the gravity of the allegations against Sandusky, but chose to cover them up.
The Freeh allegations, Spanier claims, hangs on a tortuous game of telephone tag in which the story about the assault in the showers changed over time. By the time Spanier learned of the incident, it was described as "horse play," he says.
McQueary first confided in his father and a family friend and physician Dr. Jonathon Dranov about what he saw. He then went to head coach Joe Paterno and told Paterno he witnessed activity of a "sexual nature."
Spanier contends that McQueary did not initially indicate a serious sexual assault had taken place. Had he done so, Dranov, as a family physician, would have been obligated to inform the police, Spanier claims.
"Judge Freeh does not mention this in his Report. Nor does he mention that the jury acquitted Sandusky of this count. Most important, he doesn't mention or explain why he never even bothered to interview Dr. Dranov, even though he knew what he would have said. Yet he has the audacity to accuse Dr. Spanier of concealing important information," Lewis said.
Lewis also introduced a letter from Gary Gray, a former football player who met with Paterno in the days after losing his job and being diagnosed with cancer. Gray says Paterno told him a similar story in McQueary described what he wittnessed in the showers as "horseplay."