Considering the real conclusion, the phrase “not exonerated” should not have been in the summary. I guess what the government is trying to say is that they have to put you through a trial to exonerate you, simply not finding any evidence doesn’t do it. Barr should never have allowed the terminology into his summary.
Mueller probably used the term in the actual report, and when the Dems see it, they would make even a bigger deal about it, and yell Cover Up! etc.