Former Eskom chairman Zola Tsotsi appeared to have changed meeting records to dissimulate his attempt to impose a suspended employee as CEO in 2015 after Tshediso Matona was sidelined.
Former board member Venete Klein told the parliamentary inquiry into the power utility that the board had been uncomfortable with a written proposal by Tsotsi to name "a young man" in Matona's post.
"It was a bitter pill for me when I discovered that he was on suspension and the chairman chose not to tell us but put forward his name to serve as acting CEO," Klein said.
She said board members persuaded Tsotsi that the young man in question was not a suitable candidate, but when she later had sight of the minutes of the meeting where this discussion happened, these were grossly inaccurate.
"I found that the minutes that had been signed off actually said the opposite, that the board wanted to bring him in and that he objected. The letter clearly says that Mr Tsotsi wanted to bring him in."
She added: "l lost complete confidence."
Under questioning, Klein conceded that the decision to sack Matona, financial director Tsholofele Molefe, group capital executive Dan Marokane and commercial and technology executive Matshela Koko for the stated reason that they might interfere with an investigation Tsotsi announced at Eskom prompted a downgrade of Eskom's credit rating by Standard and Poor's.
She defended the board's support for placing former CEO Brian Molefe on a full pension, though as a fixed-term employee he did not qualify for the benefit.
Molefe appeared at the time to be the best, if not the only person, able to stop load-shedding and stem the financial losses of some R400 million a day that accompanied the scheduled blackouts, she said.
"It was the first time that the glass looked half full," she said.
Klein said she relied on assurances from former company secretary and head of legal Suzanne Daniels that the exceptional pension arrangement had been above board.
It saw Molefe claim a retirement package of R30 million when he left the company in late 2016 after he was fingered in former Public Protector Thuli Madonsela's report on state capture.
"I relied on Ms Daniels. I had no reason to suspect it was not correct," Klein said.
Tsotsi was chairman from 2011 to 2015. The suspension of the four senior executives eventually led to the secondment of Molefe and now suspended chief financial officer Anoj Singh from Transnet to Eskom.
Molefe was expected to testify before the inquiry later on Tuesday.