Calgary Herald business columnist Deborah Yedlin launches a series of zingers today against Ron Brenneman, the president and CEO of oil giant Petro-Canada. Why the barbs? The Ontario Teachers’ Pension Plan, a major Petro-Canada shareholder, is poised to make a major issue of Petro-Canada’s lackluster performance during the now-faded oil boom. Of Brenneman, Yedlin writes: “It’s not that he is not capable or disliked, only that he is increasingly seen as ineffective.” Ouch. “There is, for lack of a better word, a ‘Brenneman discount’ in Petro-Canada’s stock,” she adds a little later. Double ouch.