To Mr. Burris, both his firing and what he sees as an attempt to smear his reputation after he went to the S.E.C. and the media, are clear-cut examples of retaliation against a whistle-blower. He said it made it difficult for him to find employment (he briefly worked at Oppenheimer and is now self-employed), but more importantly, sent a powerful warning to any other JPMorgan broker contemplating cooperating with the S.E.C. or speaking out about unethical behavior. He has turned over his findings to Finra, which is investigating the matter, and to the S.E.C.’s whistle-blower office.

JPMorgan sees the matter entirely differently. Mr. Burris was a rogue broker who was fired for legitimate reasons having nothing to do with his reluctance to sell JPMorgan products, a view backed by the arbitration panel. “His story is utterly wrong. He was terminated because he broke serious compliance rules in important ways and on numerous occasions,” said Patricia Wexler, a JPMorgan spokeswoman.

The firm acknowledges that Ms. Gavin actually drafted the Wiley and Scott letters after the customers came into the branch with complaints, but said she was doing so simply as a courtesy.

Even though the bank determined that neither complaint had merit, it was nonetheless obligated by law to file Mr. Scott’s letter with Finra. And, with respect to Ms. Kazmi’s testimony that no one at JPMorgan had drafted the letters, she “answered truthfully based on what she knew — she did not realize that anyone had provided the customer with the courtesy of typing up a verbal complaint or issue,” Ms. Wexler said. She said no one at JPMorgan had interviewed any of Mr. Burris’s clients to get their version of events.

At the center of these differing views is Ms. Gavin. On her website — moneywisdomandfaith.com — she describes growing up in a mobile home outside Chicago and putting herself through college and business school. She says her mission is to “work with purpose-driven Christian women and help them understand and apply the biblical financial principles of stewardship, wealth building and legacy thinking.”

She was interviewed by JPMorgan lawyers and originally listed as a witness in the arbitration, but after Ms. Kazmi’s testimony and the questions about the letters’ origins, was never called to testify.

Some questions: Did Ms. Gavin routinely write up complaints for other customers who came into the branch? Or were the sole instances those involving Mr. Burris? Was it Ms. Gavin’s idea to draft and file the letters, or did others encourage her to be on the lookout for evidence that could be used against Mr. Burris?