At a news conference Friday announcing indictments against allies of New Jersey's Republican Gov. Chris Christie -- but not Christie himself -- in the 2013 lane closures at the George Washington Bridge, New Jersey U.S. Attorney Paul Fishman suggested that no Christie-appointed lawyers in his office worked on the case. But at the same news conference, a federal law enforcement official publicly thanked a top Christie-appointed investigator in Fishman’s office for his work on the probe.

Asked if his office faced any challenges in preserving its independence -- considering its deep ties to Christie, who was his predecessor as U.S. attorney -- Fishman said: “There’s nobody who was working on this case in my office -- no lawyers working on this case in my office -- who was hired by Gov. Christie. Not one. And that’s not entirely an accident.”

Minutes earlier at the same news conference, however, the FBI’s Newark chief, Richard Frankel, thanked investigator Thomas Mahoney for his work as a "supervisory criminal investigator" on the case. International Business Times reported Thursday that federal documents show that Mahoney was appointed by Christie to his position in the U.S. attorney’s office on Oct. 1, 2006. Additionally, the Newark Star-Ledger and Main Justice have previously reported that the office’s criminal division chief Thomas Eicher was also involved in the case. Eicher was appointed by Christie on Sept. 7, 2003.

In all, documents obtained by IBTimes show that almost 40 percent of Fishman’s staff are Christie holdover appointees, which has led some New Jersey officials to question whether the office is sufficiently independent of Christie to conduct an impartial investigation of the governor.

Asked about Fishman’s comments, a spokesman for the New Jersey U.S. attorney’s office, Matthew Reilly, told IBTimes: “Tom Mahoney worked on the case, but he is not a lawyer. None of the [assistant U.S. attorneys] assigned to the case were hired by Gov. Christie. Tom Eicher was not assigned to the case.”

Fishman announced Friday that David Wildstein, hired by Christie as director of capital projects at the Port Authority of New York and New Jersey, had pleaded guilty to his role in coordinating the politically motivated traffic jam in Fort Lee, New Jersey, in September 2013. Fishman also declared a grand jury had indicted Bridget Anne Kelly, who had served as Christie’s deputy chief of staff, and Bill Baroni, deputy director of the Port Authority, for their alleged participation in the lane closure scheme. Christie, though, was not among those implicated by Fishman’s office Friday.

Fishman said even if Christie appointees worked on the case, he has “enormous confidence” that the investigation has proceeded in an impartial way. Fishman said it “would be inconsistent with every single way in which I have thought about this office and the way I have conducted myself -- both as a law assistant, as a supervisor or as the United States attorney -- to take an action, to begin an investigation, that would compromise the way the public perceives us.”

“The way our office is perceived by the public is critical, and if the public can’t have the confidence in what we do, if I can’t be proud of, if I can’t be confident in the people who are working for me, and be completely convinced that every decision they are making is in the best interest of the case, and obtaining a fair, thorough, comprehensive and just result, then I’m not doing my job and I should quit,” Fishman said.