What’s Up With the Ending?

"Justitia fiat, ruat coelum!" Or, "Let justice be done, though the heavens fall!" Some smart Latin-speaking person probably said that. But is justice done in the conclusion of Agatha Christie's Murder on the Orient Express?

When the novel ends, Poirot offers us, the readers, two possible solutions to the murder mystery. They are:

Option #1: An intruder entered the train and murdered Mr. Ratchett.

Option #2: Nearly everyone on the train conspired to murder Mr. Ratchett/Cassetti in order to bring him to justice for the murder of Daisy Armstrong.

Asked to serve as judges of the matter, M. Bouc and Dr. Constantine pick Option #1. Yes, it is clear to them that the truth is actually Option #2, but in this case, the version of events that they will offer to the police is Poirot's first solution. In other words, they decide that Ratchett's death was not murder, but a case of justice served.

So, what do you think? Was justice served? Which solution would you have picked?