The aide, Bridget Kelly, was let go in January after emails revealed she set a traffic jam plot in motion with an email saying, "Time for some traffic problems in Fort Lee," a New Jersey town at the base of a heavily traveled bridge where the tie-ups were created, apparently for political retribution against a Democrat who didn't endorse the Republican governor.
READ: A Timeline of the George Washington Bridge Scandal
Fred Kanter, a Boonton business owner at the town hall, asked the question and told the governor that Kelly should have been fired for the act of tying up traffic, which delayed emergency vehicles, school buses and thousands of commuters.
"There were lots of reasons for the firing," Christie replied. "If she had told me the truth, she would have been fired too, because of what she did."
"What happened was absolutely unacceptable," Christie added, and went on to deny involvement as he has repeatedly. "I didn't know anything about it and if I had, I wouldn't have permitted it."
The scandal has overshadowed Christie's administration, lowered his poll numbers, stalled his agenda and raised questions about his chances in a 2016 presidential race.
The U.S. attorney's office is conducting a criminal investigation into the lane closings and other allegations of wrongdoing by Christie aides. New Jersey lawmakers are also investigating, and Christie has hired an outside lawyer to conduct an internal review.
The governor, 51, has been carefully controlling his appearances since the scandal broke open this year. He has attended private, out-of-state fundraisers as president of the Republican Governors Association, and restricted in-state appearances to town hall events in Republican-friendly areas where he takes no press questions.
Hecklers who disrupted two prior town halls were in the audience again Thursday, seated together to spell out the word "Bridgegate" on T-shirts they wore. But they did not disrupt the event.
Afterward, one of the protesters, Fran Ehret, formerly head of a toll-takers union, said critics would continue to attend Christie events.
"There are some important questions he should be answering," she said, such as why Christie continues to stand by David Samson, the chairman of the transit agency who runs the bridge and a close Christie ally who ran the governor's transition. He faces allegations that clients of the private law firm he founded benefited from votes he made at the agency.
The protesters have also criticized Christie for being too slow in distributing Superstorm Sandy relief aid. The state is waiting for a second allocation of $1.4 billion from Washington.
