In Italy, aviation accidents are not investigated by an aviation accident investigation board, but by an appointed judge.
Because a judge is a layman, as far as aviation accident investigation is concerned, he may hire in, accident investigation professionals.
Those professionals will write a technical investigation report.
The judge will then decide, what HE considers to be the cause of the accident - whether HIS judgement is congruent with the result of the technical investigation, is a matter of conjecture.
The present ruling seems to be that the Italian state is culpable, thus shall pay compensation, because it failed to guarantee the safety of the Itavia DC-9. That failure to guarantee the safety, may be seen as a correct identification of the situation - after all, the DC-9 did crash, not as a result of an accident, but as result of a deliberate action.
The deliberate action however, WAS NOT A MISSILE, BUT AN EXPLOSIVE INSIDE THE DC-9. So much was the conclusion of the technical investigation of aviation accident investigation experts (and yes, those experts know about non-aviation like things such as explosives, they had Lockerbie under their belt already).
For interested readers, again the link to the real facts:
Supplementary paper offered to ISASI Seminar, Paris, October 1994
For the rest: keep revelling again about the mysterious fighters, etcetera.