1. I'm not saying Burger/Johnson are lying. I think they were credible witnesses. I'm saying that they were mistaken as to whether the screams were male or female.
2. The whole point is that the help help help came BEFORE the shots (listen to burger's testimony). Therefore, he would have had to have come up with this intruder defence before he shot her. That's just nonsense. I agree that its the best defence possible, but I think its totally implausible that he came up with the idea before/during shooting her and went to the lengths of creating his defence/alibi by screaming out for help.
Its also not right to say that burger didn't say the man screamed. She said in her examination in chief that the man screamed for help (link below at 45 mins in):
https://www.youtube.com/watch?v=3e9aUB5a4Ig
In Afrikaans Dr Burger said the man "het om hulp geskree" which means the man called for help. The interpreter incorrectly uses the word "scream" so at 45:50 Dr Burger corrects the interpreter who then corrects the translation and says the man yelled for help.