John Carlin informed the FISA Court that when he stepped down that the DOJ & NSC often used false information to obtain FISA warrants.
That would of been back in Sept/Oct 2016.
Mike Roger's instigated IG investigation, & as well informed the FISA Court of the findings.
My take trying to read through the various reports and FISA document was it could go both ways.
A possible whistleblower.