Maybe it's just me, but I'm stuck on that aspect of it.
Assuming Junior went to the FBI, what could they do on such thin information? 'Ok, thanks Junior, we'll get back with you on that?'.
Junior had to take the meeting to find out if there was dirt. So, you have to *assume* Junior wouldn't have gone to the Feds if he found out something. What if it was something so bad Junior would feel compelled to report it?
I don't think a prosecutor would touch this because it forces too many guesswork assumptions about what Junior intended to do with the dirt *after* he received it. The only thing known for sure is was willing to hear it.
Krauthammer is usually a better thinker than this. Kinda/sorta collusion is untenable. It's a charge the partisans make because it's politically expedient for them to make it. If you don't collude all the way, you haven't colluded. 'Attempted collusion' is nonsense. Just because I jumped off the roof and attempted to fly doesn't mean I flew lol.