Of course, the other issue here is whether or not the “collusion” itself would have been a crime in the first place. Mueller’s appointment needed a crime and there still hasn’t been a crime in these proceedings.
Rosenstein very clearly updated the Special Counsel reach to include Manafort. That was the weasel realizing the Russia garbage had no basis in any criminal law. He even added the “any other crimes that come up” making this the greatest witch hunt in history. The President was given horrible advice the first year to not challenge this.