Labor, defamation
No arbitrary breach of the duty of fair representation by the union, as the lack of advocacy stemmed from union's considered adverse decisions on credibility.
No actual malice in statements about plaintiff, as conclusions were reasonable from facts.
http://www.ca6.uscourts.gov/opinions.pdf/16a0016p-06.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.