Mueller had no clue how the emails got from the DNC into Wikileak's hands. That is why he never claims he did find out, because he never did. Mueller did lie, or else one of his Hillary-loving, Trump-hating democrat hound dog prosecutors lied for him in the report. Mueller's report says Papadopolous told Misfud about "Russian possession of DNC emails."
In late July 2016, soon after WikiLeaks’s first release of stolen documents, a foreign
government contacted the FBI about a May 2016 encounter with Trump Campaign foreign policy
advisor George Papadopoulos. Papadopoulos had suggested to a representative of that foreign
government that the Trump Campaign had received indications from the Russian government that
it could assist the Campaign through the anonymous release of information damaging to
Democratic presidential candidate Hillary Clinton. That information prompted the FBI on July
31, 2016, to open an investigation into whether individuals associated with the Trump Campaign
were coordinating with the Russian government in its interference activities
(Mueller Report, Vol. 1, p.9)
That was a lie. The truth was that Misfud told Papadopolous the lie first and if afterward Papadopolous said anything of the sort it was because he got his info from the lying Misfud. We know Misfud lied and set Papadopolous up from other knowledgeable sources.
While he was in Washington, the FBI approached Mifsud in the lobby of his hotel and questioned him about his interactions with Papadopoulos, prosecutors have said. Mueller wrote in his report that the Maltese professor made various inaccurate statements but that lies Papadopoulos had told the FBI about his interactions with Mifsud when he was interviewed 12 days earlier “undermined investigators’ ability to challenge Mifsud.”
https://www.washingtonpost.com/poli...74fe8c-8185-11e9-bce7-40b4105f7ca0_story.html
Did Mueller or his team examine the DNC computers themselves to determine how Wikileaks got the emails? No. Did Mueller or his team question Assange, who had offered to give them a sworn statement about the emails? No. Did Mueller or his team contact the NSA about what they had on the DNC emails, Assange and Seth Rich? No. Mueller and his team simply blindly accepted the report issued by "Two unnamed federal agencies" as to how the emails left the DNC. Strangely, Mueller does not mention that those "two federal agencies" never examined the DNC computers themselves and that Obama had said of their assdessment that the opinionated fact-less conclusions "were not conclusive."
A New Report Raises Big Questions About Last Year’s DNC Hack | The Nation
That fall, two federal agencies jointly announced that the Russian government “directed
recent compromises of e-mails from US persons and institutions, including US political
organizations,” and, “[t]hese thefts and disclosures are intended to interfere with the US election
process.” After the election, in late December 2016, the United States imposed sanctions on Russia
for having interfered in the election. By early 2017, several congressional committees were
examining Russia’s interference in the election
Mueller Report, Vol. 1, p.9.