The internal probe that exonerated New Jersey Gov. Chris Christie of any involvement or knowledge in the George Washington Bridge scandal did not settle a key question: when did Christie find out about the closures?

It could all come down to what happened during a Sept. 11 memorial event that Christie attended along with David Wildstein, a former port authority official who was allegedly involved in conceiving and orchestrating the lane closures as political revenge. The closures paralyzed traffic in Fort Lee, N.J., for several days.

Wildstein says he told Christie, but Christie says he has no memory of the conversation, according to a report released today by lawyers appointed by Christie to conduct an internal investigation.

According to the report, Wildstein told Christie's press secretary Michael Drewniak as early as December that he had mentioned the lane closures to the governor during that 9/11 event.

"It will apparently be Wildstein's contention-as he alleged in early December 2013 to Drewniak-that he mentioned the traffic issue to the governor on that occasion," the report states.

Drewniak told Christie's lawyers that he and Wildstein discussed this alleged conversation with Christie during a dinner in early December.

"Wildstein claimed that he had mentioned the traffic study to the governor at a public event during the period of the lane realignment," the report sates.

Photographers caught the two men together at the event, which occurred in the midst of the nearly week-long lane closures.

And Christie, according to the lawyers, recalls seeing Wildstein at the 9/11 memorial event.

But according to the report Christie also asserts that doesn't recall the conversation about traffic problems in the town of Fort Lee coming up at all.

"Not surprisingly, the governor has no recollection of such an exchange," the report adds.

This could be a classic he-said-he-said, but the report relies exclusively on Christie's denial to conclude the conversation was unlikely to have occurred.

The report added, however, that even if it did happen, traffic problems wouldn't have been something Christie would remember.

"A mention of a traffic issue in Fort Lee would not have been memorable or meaningful to the governor," said Randy Mastro, lead attorney at the firm Gibson Dunn, which conducted the inquiry. "It's a common occurrence to have traffic issues and problems in the bridges and tunnels. It would not have registered with the governor."

Wildstein's lawyer suggested in a letter to the Port Authority in January that "evidence exists" that Christie knew.

If that claim is substantiated, the scandal may be far from over for Christie.

(Mel Evans/AP Photo)