I don't think it's programmed that you blow up. It's just Freelancer programmers didn't think there would be a need to travel 700K+ from system center. Somehow the position of the ship becomes unstable. You will see after 5-600K that you are shaking. After some time the game just can't take the distance and kills you. My knowledge on this is a thin but it is sort of how it works.
That's sure that it happens somewhere around 700K from system center but it's not a definite value. Once I happened to blow up in my bomber BEFORE the miner I was chasing.