This is along the lines of Trolley Problem, or the scenario of convicting an innocent person to save many lives. I use the OJ Simpson trial only as an example of a high profile trial. One could substitute the Nixon impeachment proceedings, or etc ....

According to the US Bureau of Labor Statistics, over the past decade there have been about 5,000 work related deaths per year in the US (in Canada it is about 1,000 per year).

So it seems reasonable, to me anyway, to ask how many people died in order to establish OJ Simpsons guilt/innocence? And was it ethical of OJ Simpson to choose to pursue legal defense? Or was the decision to prosecute ethical?

There are various scopes and ways to calculate the number of people who died to produce the verdict. The exact number is not important. The trial invoked a huge amount of economic activity, so I'd guess the number is significant, say 1/2 a life? 1/10th a life? 

Similarly, if on average US workers work 50 years, at 2000 hours per year, or 100,000 work-hours per lifetime, then how many lives did it take to establish his guilt/innocence? And were the decisions to prosecute/defend ethical from that standpoint?