Commonwealth Bank chief executive Matt Comyn told parliament a whistleblower was made redundant “a significant period of time before any allegations were raised” when the employee was in fact sacked a little over a month after raising concerns with the company.

Comyn, who faces shareholders at the bank’s annual meeting on Wednesday, was questioned about whistleblower Tim Cradock during parliamentary hearings in October last year.

Cradock, who is suing the bank in the federal court for failing to protect him as a whistleblower, was sacked in April 2013 after making complaints that he was bullied by his manager and that staff were using two scams to beef up their bonuses.

In one of the alleged rorts, staff were swapping internal referrals to make each other’s performance look better, while in the other they met a benchmark by depositing loose change left behind in the branch into Youthsaver accounts to activate them.

The CBA denies Comyn misled parliament. A spokesman told Guardian Australia that Comyn’s answer referred to allegations raised by Cradock in 2017, when he was granted whistleblower status.

“Matt Comyn’s response was that Tim Cradock’s redundancy occurred a significant period of time before he raised his allegations as a whistleblower,” a spokesman said. “This is correct.”

Cradock declined to comment because the case is before the court.

However, his wife, who asked to remain anonymous because the couple have school-age children, said her husband’s life had been turned upside down after he was sacked and “marched out of the building like a criminal”.

“My ambitious, positive, energetic and fun-loving husband had vanished and in his place was a humiliated, reclusive and physiologically broken person (although at the time he didn’t want to admit it), a mere shadow of his former self,” she said.

Documents obtained by Guardian Australia show that Cradock, who worked in a part of the bank specialising in marketing to multicultural communities, first complained to the bank’s human resources department on 26 February 2013.

In a 12-page letter, copied to Comyn, who was head of retail banking at the time, Cradock claimed he had been bullied by his manager, raised concerns about the use of referrals to artificially boost performance measurements and complained that the bank’s management of his division.

He updated his complaint on 16 March 2013, adding concerns about the Youthsaver issue and again sending it to Comyn.

However, Comyn told parliament his “only involvement” with the Youthsaver issue at this time was an email that was sent to all branch staff a few days earlier, warning them against the practice.

“I did nothing to go further into the subsequent investigation, and if I had my time again I would have,” Comyn told parliament.

CBA’s HR department dismissed Cradock’s bullying on 27 March 2013 and he was dismissed a week later on 3 April.

The bank’s spokesman said that Cradock was sacked as the result of a redundancy program that “had already commenced rolling out in the months before the original complaint was lodged on 27 February”.

“He was not considered a whistleblower at the time, nor did he describe himself as one.

“His HR complaint was investigated and found to be unsubstantiated before his employment was terminated due to a redundancy arising from a restructuring. Both the restructuring and the redundancy were unrelated to his complaint.”

The bank eventually recognised Cradock as a whistleblower in 2017 and hired law firm Minter Ellison to investigate his claims.

Cradock’s wife said she questioned how the Minter Ellison investigation could be independent when the law firm also represented CBA in a rate manipulation case brought against it by the corporate regulator.

She said that “whistleblower policies and processes are great in theory but when they are blatantly used to cover up misconduct at the most senior levels of an organisation they aren’t worth the piece of paper they are written on”.

“Change can and should be driven from the top. Unfortunately, a fish also rots from the head down.”

CBA is defending Cradock’s lawsuit, which returns to court next month for a case management hearing.