A recent memo by the NLRB General Counsel makes it easier for workers to take action against their unions for negligence. All labor unions have a duty to fairly represent their members in filing and prosecuting grievances. A breach of that duty is an unfair labor practice. But after a fumbled grievance, unions could traditionally assert a "mere negligence" defense.
However, the General Counsel's position is that negligence can rise to the level of arbitrary conduct necessary to find that an unfair labor practice occurred. Going forward, unions will be required to show that they have procedures in place to properly track grievances. There is no bright-line rule, though, so any analysis will depend on the facts of each case.
But how does this affect Michigan public employees and their labor unions? That's not exactly clear. In many cases, the Michigan Employment Relations Commission relies on national precedent. So all unions and their workers should be on the lookout.