Short answer, yes. Longer answer- how many times had any of the witnesses heard a man screaming in desperation? And how many times had they heard a woman screaming for her life? And where had they heard any of these- in real life?on TV/film? I believe that it is clearly possible, (given all the witness evidence, timelines, the fact that a witness mistook pistorius crying for a woman etc), that in the early hours of the morning, two couples jumped to the wrong conclusion when trying to make sense of what they heard.