In the case of Regina v Dudley and Stephens. Before killing Parker the cabin boy.

1) Could they have applied existing precedents whom is going to die first ?

2) What would happen if they asked the consent of Parker before killing him?

3) How would the case be different if there was a different method of selection?

4) The Fairness of the selection criteria was biased. Whether the criticism would have been the same?

I need opinions supported by facts.