National Union of Metalworkers of South Africa (NUMSA) obo Nganezi and Others v Dunlop Mixing and Technical Services (Pty) Ltd and Others (DA16/2016) [2018] ZALAC 19; [2018] 10 BLLR 961 (LAC); (2018) 39 ILJ 2226 (LAC); 2018 (6) SA 240 (LAC) (17 July 2018)