There is nothing Strzok or Comey did that was so wrong it could have prevented an investigation into the relationship between the Trump campaign and Russia had PAPERWORK been completed differently. The Russia investigation was begun because RUSSIA HACKED THE DCCC AND CLINTON CAMPAIGN TO PUT TRUMP IN THE WHITE HOUSE AND RUSSIA SUCCEEDED. The investigation went forward as it should and the Special Counsel Report is damning of the Russians and the perjury of Trump.
FBI protocols are rules, not law. Sometimes protecting a democracy requires bravery beyond the rules.
Graham, Trump and Barr have nothing but disciplinary procedures on their hands. If Comey and Strok decide to testify beyond their 5th amendment rights we might find out why any breach in protocol was NECESSARY.
If Graham, Durham, or Barr seek to exonerate Russia from EVIDENCE of hacking that is treason. They should be very careful about their purpose.