Your phrasing is weird. In this case, the two are not in conflict but rather symbiotic - this grand jury chose to preserve the life of the person who was being accused of protecting our privacy. There is also a good chance that privacy (evidentiary rules) helped preserve this person's life.

But also you're going to have to elaborate what you mean by life being considered the highest value. Have you seen how we treat one another? We're always looking for rationales as to why someone else's life should be considered unimportant.