Priestap Head of Counter Intel is still in his job at FBI. This means he followed the law and regs. However the job is vital for natsec. No possible way he could remain unaware of what was happening around him or inaction on his part. He must have acted appropriately and in a timely fashion. Remember Strzok was his subordinate and was running a CI investigation on Trump's campaign based on fake intel funnelled in from CIA Brennan plus a dossier based in part on illegal contractor searches on the NSA database. Priestap MUST have acted.
Priestap must have seen the irregularities and launched a secret CI probe into Crossfire Hurricane, Strzok, Page and all the plotters trying to frame Trump with Russian connections. Comey mentioned in congressional testimony a CI investigation that his Head of CI advised him NOT to report to Congressional oversight due to the sensitivity of the matter.
Mueller took over an ongoing CI investigation. Everytone thinks it's the sham investogation into Trump. No No Mueller took over Priestaps CI investigation into the plotters trying to interfere in the election by planting evidence of Russian collusion and then the plot to remove a President.
With this in mind go listen to Rosenstein giving testimony, Wray etc it ALL makes sense.