Yeah my gut feeling is Nel is going to destroy Pistorius when he takes the stand, i'd be amazed if Oscar can sleep at night right now.
IMO by the time Nel gets his crack at OP, Roux will have reduced him to a pathetic figure, so damaged by his life experiences as a vulnerable, disabled man that shooting the mythical intruder was rational in his terrified mind. IOW, Nel will be left to cross-examine a pitiful, emotional wreck, whose public macho persona Roux has deftly destroyed.