For three weeks, Gov. Kate Brown had the perfect opportunity to play the part of a state executive who demands accountability, protects taxpayer dollars and acts like the governor Oregonians deserve.

But for three weeks, despite knowing that the Oregon Health Authority overpaid its 16 health care partners $74 million in federal dollars from 2014 to 2016, she has failed at basic responsible management. She kept quiet about the misspending, going public only as The Oregonian/OregonLive was preparing a story exposing the overpayments. She glossed over the fact that the federal government, which provided the money that went to health care partners, has already demanded $10 million back from the state and could seek the rest. And she ignored the troubling decision that someone in the state made in 2016 to let the private and nonprofit partners just keep the remaining $64 million in public dollars.

Only on Tuesday, after Republican gubernatorial opponent Knute Buehler urged her to claw back the money and initiate an independent investigation, did Brown finally, sort of, take a stand. In a letter to Oregon Health Authority Director Patrick Allen, she directed him to "seek repayment" of the $64 million from the coordinated care organizations. As belated as the directive is, it's a good call. As Janet Meyer, the chief executive of Portland-based coordinated care organization Health Share of Oregon noted to The Oregonian/OregonLive Editorial Board, the state has the authority to demand the money back.

It should have done so already.

The governor shouldn't stop there. As distasteful as it might be to follow the lead of her rival, she should appoint an independent investigator. The mystery surrounding who authorized the care organizations to keep money that didn't belong to them alone merits an inquiry — particularly considering their prominence as regular campaign contributors to Brown and others. Also puzzling is the fact that Brown said she was never told of the mistake or the requirement to repay the federal government until mid-October, an omission that, one might think, would concern her as the state's top elected official.

But the overpayments fiasco marks yet another sign of persistent mismanagement in Oregon's Medicaid expansion. In this instance, the state over-billed the federal government for Medicaid patients who were also eligible for Medicare coverage. An investigation can and should focus on how these errors occurred, why they escaped notice for so long and ways to improve practices or processes.

Unfortunately, the governor's not interested in an independent investigation. Berri Leslie, Brown's deputy chief of staff, told The Oregonian/OregonLive Editorial Board that the governor trusts her new director, Patrick Allen, to sort through the problems, understand the scope and identify what needs to be corrected.

"We're confident that Pat and his leaders at OHA will be able to get to the bottom of these questions," she said.

It's great that Brown is confident. The public, on the other hand, has witnessed too many meltdowns at the agency, from the never-launched Cover Oregon fiasco to the inclusion of tens of thousands of people who were no longer eligible for Medicaid to feel that confidence. Even with Allen's solid reputation. Not to mention, Allen and his team oversee a massive operation that won't allow them the focused attention they need to pin down the whos, whats and whys of the overpayment flub. And as a political appointee, Allen inherently lacks the independence that's critical for the credibility of any review, particularly of such a politically sensitive issue as this.

Certainly, Buehler's making political hay with his call for an investigation. But that doesn't mean he's wrong. Brown should cut her losses, confront the controversy and appoint an independent investigator.