Structurally, the bank was too decentralized, with department heads like Tolstedt given the mantra of "run it like you own it", and enjoying broad authority to shake off questions from superiors, inferiors, or lateral colleagues. Wells was aiming for as many as eight financial "products" per household.
For example, when the scandal first broke, Wells said it had fired roughly 5,300 employees as a result of the sales practices, the vast majority of them rank-and-file employees.
Because of the bank's decentralized structure, the problem went unnoticed for a long time.
A Wells Fargo sign is displayed in downtown Los Angeles.
It said Mr Stumpf had been "too slow to investigate or critically challenge sales practices" at the bank, or to "appreciate the seriousness of the problem". Nonetheless, her name is mentioned 142 times in the report.
Additionally, the review - which relied on hundreds of interviews and the analysis of millions of documents - found an unwillingness among executives, including Tolstedt and Stumpf to change the sales model or recognize the issues. According to the report, as recently as May 2015, senior management told the board that only 230 employees had been fired for sales practices violations. As president and chief operating officer, he became Tolstedt's immediate supervisor in November 2015. According to the report, investigators found that the bank's senior leaders "distorted the sales model and performance management system, fostering an atmosphere that prompted low-quality sales and improper unethical behavior". "So over time maybe it will grab back a little bit of its relative valuation but at this point investors have appropriately discounted all this sales scandal into the stock price", said Siefers, a principal at Sandler O'Neill. But many others "left due to their concerns", or as a result of the bank's longtime emphasis on selling more products, he said. Within the community bank, Tolstedt encouraged an aggressive sales culture, pursing rising targets that some managers complained weren't attainable. Last week, influential proxy advisory firm Institutional Shareholder Services urged shareholders to vote against the election of 12 of the 15 board members at the upcoming annual meeting, including Sanger. The directors do not plan any further firings or clawbacks, board chairman Stephen Sanger said in a conference call with reporters Monday.
The language Wells Fargo's board uses to describe each leader makes this clear.
Stumpf, who retired in October, exercised all of his remaining options and converted them to stock, which he retained, in the months before Wells Fargo announced its regulatory settlement.
ABC News has been unable to reach either of them.
"Tolstedt never voluntarily escalated sales-practice issues and, when called upon specifically to do so, she and the community bank provided reports that were generalized, incomplete and viewed by many as misleading", the authors wrote.
The board said "the investigation identifies cultural, structural and leadership issues as root causes of improper sales practices". "Certain managers made meeting scorecard requirements their sole objective, a tactic referred to as 'managing to the scorecard, '" the report said.
Since at least 2011, according to authorities, Wells Fargo employees opened as many as 2 million unauthorized checking and credit card accounts in almost every state it does business.
In the report Well Fargo's board said they would claw back an extra $US75 million in bonus payouts on top of millions already denied senior executives involved in the scandal.
He later boasted of even higher numbers, such as 6.17 in 2014 - as Sen. This demands answers. Elizabeth Warren, are you listening?
The board's report recommended that Stumpf and Tolstedt have additional compensation clawed back for their negligence and poor management. The bank remains under investigation in several states, as well as by the Securities and Exchange Commission, for its practices. He and his committee members didn't get much support from the rest of the board, the investigators imply, even after Hernandez concluded that Tolstedt had been "intentionally misleading the board".
Last year, the Consumer Financial Protection Bureau (CFPB) fined Wells Fargo $185 million, including a $100 million penalty the bank will pay to the CFPB's civil penalty fund - the largest fine ever levied by the regulator. To assist the special committee, the group retained law firm Shearman & Sterling.
"We still have a few loose ends, but we don't think it's likely to change any findings", he said.