I believe that Captain Oram had to make a decision, and he had to make it fast, as the air in the submarine was being quickly depleted. This justified his actions because if he did not make a quick decision they all would have died from asphyxiation. It was his responsibility, as the commander of all the men, to make the decision of who should live and who should die. I feel that if other people were put into his position, they would likely make the same decision as the Captain.
He needed to decide who should live and who should die. This would have been a very difficult decision as he would have needed to think of what kind of person they were, and who depended upon them. Only a small number of men could be rescued, as there was not enough oxygen for them all to survive. It is for this reason that I think he chose the married men, because they had families which depended on them and would most likely be devastated upon their death.
As Captain, he needed to act as a strong leader who led his crew well. I believe he did. The proof of this is the fact that he remained very calm and developed a well justified plan. He ensured that his crew was calm, so that they would not panic. Another fact that proved he was a good leader is that he sacrificed himself, along with the others, instead of selfishly killing another man to keep himself alive.
Lieutenant Captain Oram made a rational, justified decision, and should not be held accountable for the killing of the rest of the men. I believe that he could have made a better decision on who should have lived. Instead of five married men, I believe that he should have saved three married men, and the two youngest unmarried men. This would allow the two unmarried men a chance to live out their lives. For these reasons, I believe that he should be announced as not guilty.