When Ken Hackett was fired from his mechanic job with Southwest Airlines in February 2017, his fellow employees passed the hat to help him get by, eventually raising $25,000 through the crowdfunding website GoFundMe.

Nearly a year later, Hackett was reinstated to his job after an arbitrator ruled he’d been unjustly fired. Southwest was ordered to cover Hackett’s back pay, minus any income he’d earned from other sources during the time he was fired.

In the eyes of Southwest, that income includes the $25,000 raised for Hackett by his coworkers, according to a letter sent by Hackett's union on Friday that accuses the Dallas-based airline of trying to deduct that amount from his back pay.

A screen capture of the GoFundMe page created to support Ken Hackett. ( / )

“They are now withholding Ken’s back pay in the amount of the [GoFundMe] account that was established to support him,” Craig Hamlet, a Southwest employee and representative for the Aircraft Mechanics Fraternal Association Local 11, wrote in a letter to union members. “This is an unbelievable abuse of your generosity. It is certain that none of you meant for your hard-earned money to be collected by the airline when you donated to support your brother in a time of need.”

In a statement Monday, Southwest said it is following “customary procedures” when calculating the amount owed to an employee who has been reinstated.

“We are continuing discussions with the employee and his union, and if we can’t resolve the discussions, we will look to the arbitrator to provide additional guidance,” Southwest said.

Spokeswoman Brandy King said the GoFundMe donations are not being included in the "current discussions." Hackett's lawyer said Monday he was unaware of the change in Southwest's position.

Hackett was terminated on Feb. 28, 2017, two weeks after a supervisor said he overheard Hackett, who is also a front-line union representative, encouraging his coworkers not to accept overtime assignments.

At the time, Southwest had accused mechanics of boycotting overtime shifts to protest their unhappiness with contract negotiations that have dragged on for more than five years. Such organized work actions are prohibited under airline labor laws and the dispute over the overtime boycott, which the union has denied existed, has spun out into an ongoing federal lawsuit.

Hackett’s case played out in front of an arbitrator, who ruled in December that Southwest hadn’t met the burden of proof in his firing as required by the union contract. Specifically, the arbitrator found that the supervisor who reported Hackett heard only a portion of the conversation and did not have any context for Hackett’s comments.

Several of Hackett’s coworkers said he was simply answering questions from members and did not instruct or encourage them to avoid overtime shifts.

Hackett found work at an aviation school during the time he was fired, and an attorney representing the union, Lucas Middlebrook, said that income will be factored into the back pay discussions.

But Middlebrook challenged Southwest's attempt to count donations collected on Hackett’s behalf as income.

“Essentially Southwest wants to take that charity from Mr. Hackett after they already forced him to be out of work for a year,” Middlebrook said.

He added that the two sides also disagree about interest calculations the union feels should be added to Hackett’s back pay.

The matter is still being fought over by Southwest and the union, with a deadline later this month to file arguments with the arbitrator who will ultimately decide the issue.