DFL Gov. Mark Dayton on Friday acknowledged that he erred by taking a campaign employee along on a state airplane trip and pledged he would not repeat the error.

"It was a technical violation of the state law," Dayton said. "It won't happen again."

On Thursday, the Minnesota Legislative Auditor looked at the governor's use of the state airplane, particularly three 2012 trips he took that combined political visits and official work. Dayton's campaign reimbursed the state for the political portion of those trips.

The auditor found that the law is unclear on whether such reimbursements are the right approach. The audit, however, did say Dayton violated the law by allowing campaign staffer Julie Hottinger to accompany him on one of the plane trips. Dayton's campaign paid for the entire cost of her journey.

"One instance out of 55 trips, one campaign employee was on the plane for events that combined state business with a campaign and we reimbursed the state for two-thirds the cost of that trip," Dayton said. "I wish we would never make mistakes but we're human."

He said that on all three trips with a political component, his campaign repaid the state.

"We followed the procedure that we established, which is the one that presidents have used through Republican and Democratic administrations," Dayton said. "We did what we thought was the right thing to do."

The audit also revealed, for the first time, that attorney David Lillehaug's firm was paid about $77,000 for government shutdown-related work in the summer of 2011. At the time Lillehaug was hired, as the shutdown dawned, the governor's office said his work would be donated, or what lawyers call pro bono.

"At the time when I said he was working pro bono he was and that was the original intent, and then the scope of his responsibilities extended further," Dayton said.

Lillehaug, a former U.S. attorney for the District of Minnesota, had long been a prominent DFL attorney when Dayton asked him to handle shutdown matters. In 2013, Dayton appointed Lillehaug to the Minnesota Supreme Court.

"We hired the best constitutional lawyer in Minnesota and he performed superbly well," Dayton said on Friday. Of the payment, the governor said: "He earned it."

Overall, the governor said that he was pleased with the audit of his office, which largely gave his administration a clean bill of health.

"This was a very good audit," Dayton said. "But of course that's not what anybody is interested in."

Rachel E. Stassen-Berger Twitter: @RachelSB