Through public statements and congressional hearings, Wells Fargo & Co. executives have regularly expressed regret for the sales-practice scandal that rocked the bank a year ago.

Behind the scenes, Wells Fargo and its outside lawyers at Seyfarth Shaw and Gibson, Dunn & Crutcher have been less repentant. The bank has vigorously contested a former California branch manager’s claim that she was fired for blowing the whistle on the sales scandal, where bank employees opened millions of new accounts without authorization.