Oh dear ! The subject of this post is the trial, not to re-do the investigation.
I suggest that you look again in the Bfu report to find your answers.
TCAS flaws have been highlighted as a result of this collision and it is very simplist to suggest, as it is done here, that the757 crew responded correctly and the Tu154 did not.
As to the supposed "gross negligence" of the controller on duty, let me just say that this view is not shared by the vast majority of the people involved in the investigation, and even ,as far as I can see, also not by the defence lawyers.
How the judge will go is still uncertain.