Mueller followed DOJ rules barring presidential indictment, but he *did* include factual conclusions about obstruction.
The Report lists 11 key incidents analyzed as potential obstruction by Trump...
Mueller concludes the Comey firing may *not* be obstruction because the “evidence does not resolve” whether Trump’s “real reason” for the firing was corrupt or not....
Mueller concludes Trump’s demand that Sessions take the probe over & prosecute Clinton was for the illicit “purpose” of restricting the probe and to “shield the President” from the investigation.
That’s obstruction.
This would seem to be what Barr wanted to get ahead of.