After Mr. Horowitz released his report, Mr. Durham took the extraordinary step of releasing a public statement about his own investigation, which was still underway, saying he disagreed with its conclusions about the origins of the Russia investigation and citing his own access to more information and “evidence collected to date.”
In his report, Mr. Durham also criticized the F.B.I. for relying on the Australian diplomat’s tip without asking more questions about the credibility of what the Trump campaign aide, George Papadopoulus, had said. But Mr. Durham also acknowledged there was “no question the F.B.I. had an affirmative obligation to closely examine” what the Australians had provided, striking a contradictory tone.
Aitan Goelman, a lawyer for Peter Strzok, the former F.B.I. agent who opened the Russia investigation and interviewed the Australians, defended the inquiry and noted the inspector general had said it was properly predicated.
“When the F.B.I. received credible information from a senior official of a close American ally that the government of Russia was interfering in the upcoming presidential election on behalf of the Trump campaign, the bureau could not ignore that information,” he said in a statement.
Mr. Durham also broached the Steele dossier, building on extensive findings by Mr. Horowitz.
In his December 2019 report, Mr. Horowitz had uncovered extensive ways in which the F.B.I. had botched wiretap applications used to target a former Trump campaign adviser with links to Russia, Carter A. Page. That included relying on allegations in the dossier in renewal applications after the F.B.I. had reason to doubt its credibility.
Mr. Horowitz also developed a criminal referral against an F.B.I. lawyer who had doctored an email used in preparation for a renewal application.
Picking up that referral, Mr. Durham negotiated a guilty plea with that lawyer, which resulted in no prison time. But the only two cases Mr. Durham himself developed, both cases of false statements against people involved in outside efforts that raised suspicions over Mr. Trump’s possible ties to Russia, ended in acquittal.