Wow. Very interesting point. Here's how I'm thinking about it: The death to any of the 5 individuals is equal to the death of the 1 innocent man. Here's where I like to think of the concept of justice. For me, justice isn't some inherent set of rules written in the stars that's objectively true. Justice is a series of rules that, if followed, happiness is maximized generally speaking. Therefore, following a just action is necessary to commit a "good" action when our value here is happiness. That being said, justice is being violated in this case: the right to life is being "stolen" or taken away which is a violation of justice. With this in mind, the concept of justice can act as a "tie breaker" here in favor of preserving the innocent. Did that make any sense? What do you think?