Otdfbt

On Page 2 of Volume II (PDF), Mueller writes:

Third, we considered whether to evaluate the conduct we investigated under the Justice Manual standards governing prosecution and declination decisions, but we determined not to apply an approach that could potentially result in a judgment that the President committed crimes. The threshold step under the Justice Manual standards is to assess whether a person's conduct "constitutes a federal offense." U.S. Dep't of Justice, Justice Manual § 9-27.220 (2018) (Justice Manual). Fairness concerns counseled against potentially reaching that judgment when no charges can be brought. The ordinary means for an individual to respond to an accusation is through a speedy and public trial, with all the procedural protections that surround a criminal case. An individual who believes he was wrong accused can use that process to seek to clear his name. In contrast, a prosecutor's judgment that crimes were committed, but that no charges will be brought, affords no such adversarial opportunity for public name-clearing before an impartial adjudicator.

(bolding added)

Doesn't this clearly state that Mueller's team made a conscious decision to NOT to evaluate "conduct" that might lead to an indictment of the President?

Yes, but. Mueller made it crystal clear that he abided by the Department of Justice policy that a sitting president cannot be indicted -- or at least should not, because it basically gets in the way of running the country. That being said, take a look at footnote #1,091, which essentially invites to indict Trump once he's no longer in office.

The text in footnote 1091 on page 178 of the second volume reads:

A possible remedy through impeachment for abuses of power would not substitute for potential
criminal liability after a President leaves office. Impeachment would remove a President from office, but
would not address the underlying culpability of the conduct or serve the usual purposes of the criminal law.
Indeed, the Impeachment Judgment Clause recognizes that criminal law plays an independent role in
addressing an official’s conduct, distinct from the political remedy of impeachment. See U.S. CONST. ART.
I, § 3, cl. 7. Impeachment is also a drastic and rarely invoked remedy, and Congress is not restricted to
relying only on impeachment, rather than making criminal law applicable to a former President, as OLC
has recognized. A Sitting President’s Amenability to Indictment and Criminal Prosecution, 24 Op. O.L.C.
at 255 (“Recognizing an immunity from prosecution for a sitting President would not preclude such
prosecution once the President’s term is over or he is otherwise removed from office by resignation or
impeachment.
”).

Also, there's a nugget on page 8 of volume II:

if we had confidence after a thorough investigation of the facts that the President clearly did not commit obstruction of justice, we would so state.

Edit: To reply to Fizz' and BobE's comments below. Rachel Maddow's April 18 and 19 episodes are interesting and instructive, as are a number of other sources, like Vox (e.g. their last The Weeds podcast and a few articles of them on the topic).

What Mueller's team did is basically say is that they cannot make a determination because of DOJ policy. This article from the Washington Post might be one of the best I read on the topic in that it spells out where the legal disagreement between Barr and Mueller resides, and explains how the latter went to great lengths to rebuke the former in his report, while letting the determination on Barr's end for political face keeping reasons. (Essentially, Barr would have overridden the decision had Mueller indicted Trump.)

Mueller's team basically deferred to Congress about the proper remedy (i.e. impeachment), and spelt out very precise descriptions that are indictments in all but form, in the name of making sure the record is kept. They also raised that a sitting president can be indicted after they no longer hold office, and investigated until then. And they raised to boot that had the president been innocent they would have exonerated him. To paraphrase Maddow's last episode (Apr 19), he basically served future prosectors a roadmap to land Trump in legal hell and likely jail (unless Trump does something until them.)

Mueller wasn't as hamstrung as you suggest. The fact that he detailed (at least) 10 probable obstruction of justice causes against Trump means obviously he did look into indictable offenses, even if he himself could not indict the president (following the DOJ doctrine that a sitting president may not be indicted).

Most of the legal and journalistic opinion I've seen interprets Mueller's report as passing the buck to Congress for acting on those findings, especially based on the quote that JJJ gave in his own anwer. See e.g. The Atlantic "The Mueller Report Is an Impeachment Referral
" or Vox quoting Miriam Baer, law professor, Brooklyn Law School: "President Trump’s supporters can call it an exoneration, but his opponents may well view it as a road map for impeachment."

The fact that Mueller suggested that Trump might even be criminally prosecuted after leaving office (in the quote JJJ added to Denis' answer) is the icing on the cake so to speak.

And if that's not enough, Mueller report also discusses whether attempted obstruction is indictable, and concludes that it is. This is quite relevant because Mueller concluded that in a lot of the probable causes his report discusses, Trump tried to do something usually by requesting or instructing his underlings, but often enough they refused to follow through. The report summarized that as:

The President's efforts to influence the investigation were mostly unsuccessful, but that is largely because the persons who surrounded the President declined to carry out orders or accede to his requests[.]

Mueller's report also dedicates quite some space (23 pages) to refuting the idea (advanced by Giuliani and Dershowitz of Trump's legal team) that a sitting president cannot obstruct justice in any acts related to the exercise of his constitutional powers. Mueller's conclusion in that regard is that:

A preclusion of ‘corrupt’ official action is not a major intrusion on Article II powers. [...] For example, the proper supervision of criminal law does not demand freedom for the President to act with the intention of shielding himself from criminal punishment, avoiding financial liability, or preventing personal embarrassment.

You can probably see now why an attorney called the Mueller report "an indictment in all but the formalities." Not only does the report cover some probable causes, but it also contains legal theory arguments why those causes would be indictable. Ultimately however, in Mueller's view, the sitting president not being indictable according to DOJ doctrine trumps those other considerations. But this is quite different from just asserting the non-indictable sitting-president issue and not bothering with any further investigation.

Doesn't this clearly state that Mueller's team made a conscious decision to NOT to evaluate "conduct" that might lead to an indictment of the President?

What the bolded statement says is that the conduct shall not be judged by the investigation, whereas you are asking whether conduct was evaluated.

The difficulty with the investigation, from the beginning, is that the alleged acts do not leave behind immediate evidence that a crime has actually been committed in the first place. There is no body, no payload of contraband, and no missing money. In a case like this one, the existence of a prosecutable offense depends on the exact timeline of events. Establishing motive depends on the investigation having evidence of what the subject knew, and when they knew it. Establishing commission of an offense similarly depends of knowledge of minute details - what was said, to whom and when.

This investigation seems to have 'evaluated' all of that in detail, per the question you have asked. Means, motive, opportunity, and in many cases an action or attempt at action has been thoroughly documented.

The details of the investigation are now in the hands of Justice and Congress. A judgement may yet be made - like any investigating officer for any policing force, the system works better if the investigator and the judge aren't on the same payroll. The two real differences between this and any other investigation are 1) the detective can't file the charges and 2) the prosecutor deciding whether or not to pursue the charges is Congress.

Doesn't this clearly state that Mueller's team made a conscious decision to NOT to evaluate "conduct" that might lead to an indictment of the President?

Yes, it does. Page 8 (page 220 in the pdf) of the second volume contains the following lines (just before the conclusion heading):

Finally, we concluded that in the rare case in
which a criminal investigation of the President’s conduct is justified, inquiries to determine
whether the President acted for a corrupt motive should not impermissibly chill his performance
of his constitutionally assigned duties. The conclusion that Congress may apply the obstruction
laws to the President’s corrupt exercise of the powers of office accords with our constitutional
system of checks and balances and the principle that no person is above the law.

I (and some American media outlets, e.g. Vox) interpret that as saying Congress should be the one to determine whether to bring criminal charges. The second volume goes into much more detail, for example under the Legal Defenses To The Application Of Obstruction-Of-Justice Statutes To
The President heading starting on page 159 of the second volume.