Silent Bob finally speaks*...
*but doesn't strike back. ;-(
I disagree. As you say, he comes from an institution whose culture was built around respectful disagreement, not public calling out. But you don't need to dig too deep to see what he said as a direct response to Trump/Barr claims:
"Witch Hunt!" - The biggest part of his statement was outlining what, exactly, Russia did to interfere in this election, while saying to Americans that this is something we should all be concerned about. In other words, this was not some frivolous investigation based on a random oppo report. And this goes right to the heart of Trump's call to investigate the investigators...its based on the premise that the investigation had no merit which Mueller came as close as he could to calling bullshit.
"No Collusion!" - Mueller pointed out that his report discusses the Trump Campaign response to the Russian meddling but could not find evidence of a "broader conspiracy." That's not "no collusion." That's collusion that was not blatant enough to charge. Even better, Muller said
"When a subject of an investigation obstructs that investigation or lies to investigators, it strikes at the core of the government’s effort to find the truth and hold wrongdoers accountable." In other words, these people did not cooperate, lied, erased emails, etc (all actions described in the report, and some charged in court) and that could be at least part of the reason he wasn't able to connect the dots to conspiracy.
"No Obstruction!" -
“If we had confidence that the president clearly did not commit a crime, we would have said so.” Mueller may have thought there was obstruction, but thought it would be unfair to make that charge with the "President" not being able to address that charge in court. But he would have said so if he thought Trump was innocent. He didn't.
Nothing new to any of this, which may be Mueller's point. Note to Democrats: Read the damn report, then do something about it. Don't depend on Mueller to bail you out of your
constitutional responsibility to make the "President" answer for his crimes.