The fact of the matter is that with the full resources of the Justice Department at his disposal, in two year investigation Mueller was unable to find any evidence of collusion with the Russians and didn't find evidence sufficient to conclude obstruction of justice. And now you guts are jonesing for more lies about the President.
Actually that is your speculation. You didn't even include a single quote from Barr.
"But as noted above, the Special Counsel did not find that the Trump campaign, or anyone associated with it, conspired or coordinated with the Russian government in these efforts, despite multiple offers from Russian-affiliated individuals to assist the Trump campaign."
This is crystal clear. There is no more clear way to state the conclusion.
"After reviewing the Special Counsel's final report on these issues; consulting with Department officials, including the Office of Legal Counsel; and applying the principles of federal prosecution that guide our charging decisions, Deputy Attorney General Rod Rosenstein and I have concluded that the evidence developed during the Special Counsel's investigation is not sufficient to establish that the President committed an obstruction-of-justice offense. "
Is also crystal clear from Barr's determination of the evidence that Muller presented. Further, it was Muller who decided to pass on making any recommendation in the report as stated by Barr:
"After making a “thorough factual investigation” into these matters, the Special Counsel considered whether to evaluate the conduct under Department standards governing prosecution and declination decisions but ultimately determined not to make a traditional prosecutorial judgment."
So, no. His statement was not 'opinion.' It was fact based on the actual letter that Barr released to the public. That Muller punted on the obstruction side of the case is not really a surprise at all - it is difficult to establish corrupt intent when Trump neither touched the actual investigation itself as there has not been a single iota of evidence showing Trump actually interfering with Muller's investigation and no actual crime was discovered in the first place.
The left is mostly hanging onto Comey's dismissal as obstruction yet that is a massive cry from actual obstruction.