I'm not buying his story either,he says he did not hear her get out of bed 2ft behind him because he was bringing in fans and they were blowing in his face but he did hear a noise in the bathroom despite the fact that it has emerged that these fans were not actually out on the balcony but placed at the doors leading onto it so he was not in a great position to hear any noise in the bathroom at that point.
I think a lot of it is pure lies but if she was trying to get away from him urgently it would have made more sense for her to run out of the bedroom and go in the other direction that would take her out of the house,i am thinking more that they never actually went to sleep that night,they argued and she was upset and possibly somewhat afraid,i think she locked herself in the toilet to try to 'escape' the arguing and he followed her shouting then shot her.
She had her arms up over her head at the time of shooting and was standing facing the door according to one expert,she may have done that to try to block out him shouting at her not thinking he would go as far as harming her.
Some people think she may have been shouting for help from the window rather than trying to get out because it was a long way down,i suppose it's possible that she went in there feeling he would not harm her but that he started to threaten her whilst she was inside so in that case you would do what you could to get out but if she was standing facing the door with her arms over her head at the time of the shooting it seems less likely that she was trying to get out of the window unless she had tried and failed already.
It's all pure speculation really though,only two people know the truth,one is sadly no longer with us and the other is trying to escape any kind of prison sentence so is not going to admit anything even if he did deliberately kill her and i am not saying he did but if that is true he will never admit it.