The report, paid for by taxpayers, was released Thursday by former federal prosecutor Randy Mastro. He told reporters that the lane closures didn't reflect the way the governor's office generally operates. Mastro described it as "the action of the few."
Some of the key figures would not cooperate with his probe. That prompted Democrats to question the credibility and thoroughness of the report.
But Mastro says his team was able to review a trove of documents, including emails and text messages involving Christie, the state's lieutenant governor, top office staff and former staff members. He says, "We believe we have gotten to the truth or we wouldn't be reporting it."
Federal prosecutors and state lawmakers are still investigating.
The report also rejects a claim by the mayor of Hoboken, who said Christie's administration told her that relief from Superstorm Sandy would be tied to a private redevelopment plan. According to the report, that claim is "demonstrably false."
State Sen. Loretta Weinberg says it "raises more questions than answers" about lane closures that led to massive traffic jams last year.
She notes that the taxpayer-funded lawyer hired by Christie's office to produce the report did not have access to the "main protagonists" in the case.
Weinberg is co-chair of a legislative committee investigating the same issues. Christie's administration has criticized that probe as biased.
The Democratic National Committee says the report is "nothing more than an expensive sham."
Christie: Never considered quitting over scandal
New Jersey Gov. Chris Christie says he never considered resigning because aides shut down traffic leading to the George Washington Bridge.
Christie tells ABC News, "I'm not a quitter."
He says he won't decide for another year whether to run for president in 2016, but says the scandal overshadowing his administration won't influence his decision and will make him a better leader.
Christie's appearance Thursday comes the day a lawyer he hired released a taxpayer-funded report clearing him of involvement in the political payback plot. A federal criminal investigation and state legislative probe are continuing.
It's the first major scandal to hit the Republican governor.
Christie hasn't held a press conference since early January, when he had to rescind a claim that no staffers were involved in the lane closings.
(ABC7 News contributed to this report)