Fact - Strzok was the person central to all of this in that he was the person who signed reports, affidavits, and he lacked any self-control so it is likely he left a paper trail via email and text from start to finish.
We will know when the OIG report comes out and until then we can only speculate, but based on what we do know from reliable media sources like Sara and John it will not be pretty.
If the OIG did not impanel grand juries to gather its information, and used traditional interview/depositions/affidavits, that report might have a ton of information the democrats aren't going to be able to whitewash.