They can claim we couldn’t tell if it was true or not and look he was even found not guilty so we are justified in pursuing his claims.

You realise that the count of lying to FBI had nothing to do with the material correctness of what he reported to them, but rather his claim that he was acting on his own behalf?

And lying to FBI is a crime because it misleads and wastes their resources. Only way to make that case is to prove that FBI was indeed misled by him. Instead Durham provided evidence by the FBI agents saying they knew the facts were wrong and still proceeded with the investigation.

Makes the original charge all the more important. Its as if Durham picked the one charge that will have no bearing on the material aspect of the case.