Well, seizing evidence that isn’t specifically related to the scope of a warrant is a 4th amendment violation. So even though the FBI is corrupt, if they took the hard drive, it would have been an unlawful seizure, and Giuliani is certainly smart enough to know that.
Correct of scope BUT according to Rudy, he told them it was evidence of a crime and as they were there lawfully it was in plain view.
This action allows the Agent and the FBI to lie about knowledge of the evidence with impunity.