Where is the Justice

It seems that Rashi is saying that had a Jew remained in his house that evening, he would not have been killed, and had he left his house, he might die – not because he was guilty of any sin, not because he deserved to die, but because once the destroyer is given permission to kill, anyone in his path is in danger.

This Rashi is quite difficult to understand. If someone is innocent, then how is it possible that he would die? The basis of our entire belief system is that there is no power in this world other than HASHEM. We accept that all decisions are directly guided and carried out by Him alone. So how is it possible that someone undeserving of death would have been killed anyway, just for going outside that evening? Where is the justice?