An industrial umpire would have lost $500,000 in superannuation if she followed the advice of a celebrity "financial guru" whose employee impersonated her on phone calls.
Fair Work commissioner Donna McKenna rejected the "risible" advice of planner Sam Henderson, whose regular media appearances include hosting a TV finance show.
The banking royal commission heard when Ms McKenna complained to the professional body for financial planners, Mr Henderson described it as a "storm in a teacup" and labelled her as hostile and aggressive.
He also asked the Financial Planning Association not to share his response as the lawyer would find being labelled nitpicking inflammatory.
Senior counsel assisting the commission Rowena Orr QC asked: "Mr Henderson, is it really nitpicking for Ms McKenna to make a complaint after receiving advice that if implemented would have cost her half a million dollars?"
Mr Henderson replied no.
A staffer of his advice firm Henderson Maxwell impersonated Ms McKenna on a number of phone calls to gain information from her super fund, with recordings of two calls played to the royal commission on Tuesday.
Mr Henderson could not recall if the staffer spoke to him while one of the calls was on hold but said he was not aware of the impersonation.
"I was quite disappointed and actually apologise for the behaviour of my staff member," he said.
"It was inexcusable. I was horrified."
The commission heard Ms McKenna would have lost $500,000 "just like that" if she had followed the advice, as she would have forfeited her rights to that entire deferred lump sum benefit if she accessed her superannuation before the earliest retirement age of 58.
Mr Henderson blamed the problems with the advice on an error in the research conducted by a paraplanner.
The commission heard Mr Henderson had wanted the FPA to keep Ms McKenna's March 2017 complaint confidential given his media presence and potential financial loss as a result of any publicity.
But the chair of its independent conduct review commission wanted tougher sanctions including a one-year ban on media appearances.
The complaint and disciplinary process has not been finalised.
Mr Henderson, described on his website as a financial guru, has hosted a Sky News Business program and regularly appears on Network Ten's The Project and the Nine Network's Today show.
The Henderson Maxwell CEO also writes general financial advice articles for a number of Fairfax publications including the Australian Financial Review and Money Magazine.
The royal commission earlier heard an ANZ financial adviser used clients' money to buy a property in the name of a company of which he was the sole director and allegedly took money from their accounts.
A number of customers of the sacked adviser of ANZ planning subsidiary millennium3 complained about unauthorised withdrawals or transfers from self-managed super funds and investments in the unit trust set up to buy the marina property.
The commission heard ANZ has notified West Australian police of allegations by three of Mr A's customers that he withdrew funds totalling $234,590 without their authority in 2011 and 2012.