For what reasons does the king consider this method fair and impartial?

In the short story "The Lady or the Tiger?" the king devises a method of punishment for those he believes have committed crimes. Each criminal will be given the choice to open one of two identical doors. Behind one door is a lovely maiden, and if this door is opened, the accused criminal will then marry the maiden. Behind the other door is a tiger, and if this door is opened, the accused criminal will certainly be mauled to death. The king feels this method is fair and impartial, as the chances for either outcome are equal. The king likely believes the accused criminal made poor choices that led them to the situation they are in where they must choose between the two doors. Using this logic, the king is able to justify his method of punishment because it will be the accused criminal's own choice that decides his fate. The king believes his method is fair because there is a fifty percent chance of life and a fifty percent chance of death once a door has been chosen. The king believes he is being impartial because the doors are identical, with no outward signs that would hint to what lies within.