FBI didn't base their investigation on Steele dossier.
We [the SCO] were aware of the Steele dossier, obviously. We were aware of some of the efforts that went into its verification... we did not include Steele dossier reporting in the report.... [T]hose allegations go to the heart of things that were in our mandate—but we believed our own investigation. The information that we collected would have superseded it, and been something we would have relied on more, and that's why you see what we did in the report and not the Steele dossier in the report.
[13]
He "declined to provide further information on whether FBI or SCO attempted to verify information in the dossier, although he noted that the SCO did not draw on the dossier to support its conclusions."