I get the scenario, but in VTs case we have no motive, he is not a rapist has a good clean record in Holland as well as in the UK, worked hard to get the PHd and good job, got a new life with lovely GF spending Christmas with her parents from 24 till 26 Dec then goes home to his family in Holland till 2 Jan, goes back to work, why kill JY, why throw it all away, his family are so shocked and love him too . I cant think of another murdered who didnt have something in their background to make them a killer if not at the least some motive
I am not saying VT is guilty that is for the Court's to decide, there has to be some substantial evidence against VT for the CPS to go with Case.
Just because someone has a Degree, loving Relatives, a nice girl friend and a good life, is not to say that they are not capable of doing this, Killer's come from all different part's of Society,
You said VT had a lot to lose, look how many murder's are committed in an act of rage, a Husband kill's his Wife or vise versa, they too have a lot to lose their Family(Children) freedom etc, but in a moment in a total loss of control and all normal reality goes out of the window, I know they were not Married, I was sighting an example of loss of control, at the time the Person committing a killing is not thinking about what they have to lose, rage consumes them and nothing else.
If VT is guilty, there is the possibility that VT never meant to kill JY, then after the act of what happened, self preservation and self survival took over.
We won't know anything until the Trail, as for the motive we may never know.
I do understand what you are saying though.