He is presumed to have been burnt to death by Vlakplaas operatives at Vlaklaagte, KwaNdebele, during July 1986. Mr Mabena and eight other youth activists had been recruited by Vlakplaas askaris for supposed military training when they were killed. The house they were staying in was set alight and the nine bodies were burnt beyond recognition. See Nietverdiend ambush.
Sorry, no references to this term could be found in the tv series transcripts.