Was it wrong though? How many US troops should we sacrifice to save one enemy civilian? In other words, if you were President Roosevelt or Truman then how do you morally justify not doing everything possible to shorten the war by even one day? How do you tell a US family that their son had to die so that the US government could avoid randomly killing innocent civilians?

It's cheap and easy to pretend to be morally superior when you're not the one forced to make hard choices based on limited information, and then deal with the consequences.