The audit, dated Feb. 27, was made public Thursday by Christie's office.
His office criticized Democrats and "complicit" media for treating the contract as a scandal last year. The overzealousness of critics and journalists is a theme Christie hit Thursday in a different context, a speech to the Conservative Political Action Committee.
In an email to reporters, Christie's office noted anger over AshBritt was "led by some of the same partisan Democrats that are attempting to politicize various issues today."
A legislative committee and federal investigators are looking into Christie's administration's involvement in shutting down of lanes near the George Washington Bridge as political retribution and complaints from the mayor of Hoboken, who said cabinet members told her city's post-Sandy aid would be tied to her support for a redevelopment project. Christie and his administration deny any wrongdoing.