Did they destroy evidence of abuse and bogus research before exiting?
Almost certainly. Expect a lot of sabotage on their way out, specially in computer software. That is NOT unprecedented, and should have draconian penalties applied.
Most millenials and other ignorant imbeciles are blissfully unaware that the EPA was created as an Advisory agency.
Then the Congress, in its infinite corrupt incompetence, surrendered its prerogatives to the criminal bureaucracies (saves on actual informed thought.)