It wouldn't matter if it was "somebody's fault."

In a two tier society like the US (the govt class vs the productive class) the government class protects their own with made up legal doctrine like "qualified immunity" which gives them carte blanche to steal, rape, and murder the productive class.

If the blame were to lie with one single individual at the FBI who committed multiple crimes effecting this illegal search that person would still not be held accountable by the courts, the FBI, nor any other government agency.