First of all there is no statute regarding collusion, so how could there be a crime? Pretty easy to be confident when you know the answer to that question, right?
Secondly, with 2 years of legal and illegal counterintel and intel ops going on, FBM and special counsel investigations going on, leaks, unmaskings, etc... and not even the first real piece of real proof against team Trump nor any nefarious Russian dealings during the campaign...and none of the leaks nor reporting are ever, ever, positive to Trump
The Muel was not chosen by both sides, he was chosen by a heavily conflicted Rosensteinks. Muel is himself overly conflicted, then he chose a team of partisan hacks, has already broken the law and is simply not out to seek truth... so its a heavily tainted investigation no matter its final report.
A thorough investigation would be investigating all 2016 election irregularities, not just the one side where there appears to be none of consequence and ignoring the blatant ones staring us all in the face.
Yano?