In general, they also have no duty to know what the law is!

That's why you give them a motto of "to protect and serve". Protection and service are very expensive, and utterances are very cheap.

sounds about right.

People in the US need to know that federal agents cannot currently be held accountable for criminal actions committed during official duties and that neither Bivens nor 1983 civil claims can be brought against federal agencies. They can and do kill people and violate their civil rights with complete impunity until Congress is compelled to legislate that federal officers are held to the same standard as local ones.

tl;dr: Federal officers can do anything they want and there's zero recourse.