And so it was that one day in the summer of 2014, Mr. Alix looked over a sheaf of court papers filed by one of his competitors, McKinsey & Company, with a sense of disbelief. The powerful consultancy had branched into bankruptcy advising, poached some of his firm’s employees and been hired by Harry & David, the seller of pear-laden fruit baskets, to advise its restructuring in bankruptcy.

Mr. Alix had long been retired, though he still held a seat on the board of the company he started, AlixPartners. As he tried to puzzle out how McKinsey had beaten out his firm for the Harry & David job, he found something strange, the kind of thing you probably wouldn’t notice unless you were a certified fraud examiner — which Mr. Alix also happened to be.

McKinsey’s filings, sworn under penalty of perjury, looked complete on the outside. But they were missing their guts: a detailed list of all of McKinsey’s connections to the other parties to the case. It’s important paperwork, meant to prevent conflicts of interest. Advisory firms have a fiduciary duty to protect the assets of the bankrupt company, and they are required by law to submit such a list to guard against back-room dealing that might harm the business’s ability to survive or reduce the payments creditors are entitled to.

Bankruptcy advisory firms like McKinsey and AlixPartners have immense power over the way a case is resolved: They influence how much creditors are paid, how salvageable parts of the business are sold, and where equipment and other tangible assets end up. If nobody knows whom else the bankruptcy adviser works with, it is impossible to know if that adviser is cutting someone a sweetheart deal.

Mr. Alix had put together hundreds of bankruptcy filings before he stepped away from his business in 2000 at age 45. His wife had died in a boating accident that year, leaving him to raise two children, ages 6 and 9. As he examined McKinsey’s filings in the Harry & David case, he wondered if the law had changed while he had been busy with car pools and parent-teacher conferences. He asked some lawyers. No, he was told, the law was the same.