I have another theory on this from personal experience. I was given a glass of wine on the back balcony of a man's home and I had met the students there before this who had gone into their bedroom.
After we had finished our drinks, he suddenly picked me up and carried me down the hall, threw me on his bed and raped me.
As soon as he picked me up, I went into shock mode and while I was conscious of what he was doing, I was incapable of calling out to the students for help or struggling.
No one could ever understand why I could not call out or kick him but I was totally paralysed with fear.
Apparently, we either FIGHT, FLEE OR FREEZE in these circumstances.
Eventually, a Psychiatrist told me that I froze in fear. (Otherwise, in hindsight he could have drugged my wine.) Few people even now ever acknowledge this fear response to trauma.
http://www.stressstop.com/stress-tips/articles/fight-flight-or-freeze-response-to-stress.php
IMO SG could have d always told Lisa that if she ever tried to leave him, he would end her life and pretend it was suicide. According to the lady who recently came forward at the sentencing hearing, this was the case.
It is such a pity she did not come forward earlier because IMO Lisa had been living with this fear for some time. I have forgotten how long ago the lady said Lisa told her this.
Therefore, as soon as SG picked her up, Lisa may have known that this was going to be the end. Who knows what he said to her at the same time? An example could have been, "Now I'm going to throw you over the balcony and everyone will think that you have committed suicide.":facepalm:
I also think due to this photo, that Simon could have practised lifting Lisa up several times before and had this plan in mind if he ever needed it. For all we know he may have threatened Lisa with it to keep her under control. The note found in her jeans is also revealing too as if she had a premonition.
Therefore, IMO Lisa would have been completely traumatised and she FROZE as she knew there was no hope.
Some of these things could have helped the Prosecution with a case for premeditated murder if that lady had come forward before the trial. In other words, the practise had been done in advance of lifting her up and it was just a matter of time for the plan to be activated if he ever needed it.