It doesn't matter what is being investigated - it is illegal to obstruct a legal investigation.

[wishstar]

8. Trump & Co knew though that Flynn had initially lied to FBI and criminal investigation was involved

Sally Flynn told WH in January about Flynn's problems regarding the Kislyak calls and gave them access to details of his FBI interview in which he allegedly lied about talking to Kislyak about sanctions but then changed his story to FBI when he realized they must have a tape. Without revealing classified info, her testimony was very clear that Flynn had substantial legal problems that FBI was investigating.

They also knew Flynn could have run afoul of technicalities of federal regulations involving his payments from Turkish and Russian entitities, as Elijah Cummings had notified them in November of potential Flynn conflicts of interest and supposedly Flynn himself had mentioned some of his Turkish lobbying actions to transition back in Nov..

So I don't see how people can claim innocence and no clear obstruction of justice when Trump was trying to get FBI to go easy on Flynn and trying to influence the other intelligence officials with regards to the investigation. He directed other WH officials such as Priebus to also contact govt officials regarding investigation in order to publicly whitewash the matter.