Newly-declassified documents show then-FBI Director James Comey purposefully lied about the Steele Dossier. He wrote an email to then-Director of National Intelligence James Clapper saying the dossier couldn't be "sufficiently corroborate[d]." Despite the lack of corroboration, Comey still signed the FISA warrant that resulted in the surveillance of Carter Page.
Below is Comey's Jan. 12, 2017 email (emphasis mine):
just had a chance to review the proposed talking points on this for today. Perhaps it is a nit, but I worry that it may not be best to say "The IC has not made any judgment that the information in the document [dossier] is reliable." I say that because we HAVE concluded that the source [redacted] is reliable and has a track record with us of reporting reliable information; we have some visibility into his source network, some of which we have determined to be subsources in a position to report on such thing; and much of what he reports in the current document is consistent with and corroborative of other reporting included in the body of the main IC report. That said, we are not able to sufficiently corroborate the reporting to include it in the body of the report.
That all rings in my ears as more complicated than "we have not made a judgement that the information in the document is reliable." It might be better to say that "we have not been able to sufficiently corroborate the information to include it in the body of our Russia report but, for a variety of reasons, we thought it important to include it in our report to our senior-most audience."
At this point in time, Operation Crossfire Hurricane – the FBI's investigation into Trump campaign officials during the 2016 election and well after the Trump administration took hold in January 2017 – was already teetering. The CIA informed Comey and the FBI that Carter Page wasn't a Russian spy. He was actually helping the CIA.
Despite the CIA's information and warnings about Steele's network potentially being compromised by Russian disinformation, the FBI went forward with their probe. This was even after the FBI was told Hillary Clinton's campaign used the Steele Dossier to distract from her email scandal. Again, they pressed on with their probe.
What makes Comey's email even worse is DOJ Inspector General Michael Horowitz's report found that Comey sent this email to Clapper on the same day as he signed off on the FISA warrant to extend surveillance on Page for another three months. Horowitz concluded the warrant had major issues.
"The FBI filed three renewal applications with the FISC, on January 12, April 7, and June 29, 2017. In addition to repeating the seven significant errors contained in the first FISA application and outlined above, we identified 10 additional significant errors in the three renewal applications," Horowitz's report said.