John Perlman, the highly respected presenter of the SABC's flagship AM Live programme, is leaving.  Although he won't say why, it seems generally accepted that he is a casualty of the corporation's blacklisting fiasco, writes Anton Harber in his Business Day column, The Harbinger.   CEO Dali Mpofu indicated earlier that heads would roll – who would have thought they would be the ones exonerated in the report by the SABC's own commission. It's a sad indication that the SABC is simply unable to play its role as a public broadcaster.