"We all agree there wasn't evidence of Trump personally colluding."
I'm not sure we can all agree with that. We could possibly agree that no charges were laid on Trump. Insufficient unredacted parts of the report were released to help us properly understand whether that was largely due to an absence of evidence or whether it was largely due to DOJ policy to never indict a sitting president. Mueller certainly implied in his report and in his testimony, that this latter point was a pertinent consideration. Bottom line, after January 20, such immunity disappears and we will see what comes of the Mueller report. There may be a 'self pardon' test case to take before SCOTUS before the report can be dusted off.
