A breakdown of the six main clues that point to the train scene having never happened
Per request, and since these points seem to keep getting missed over and over in so many discussions and comments about that scene:
There was no diary entry about the train scene. If you actually examine the scene in episode 1x06, there is not one single diary in the room in the Dubai scenes with Daniel and Louis during the interview scenes in that episode. And there is not one single diary present when Louis starts talking about the train scene specifically. Louis is not reading from a diary. Daniel is not reading from a diary. None of Claudia's diaries are present at all in episode 1x06.
In both Season 1 and 2, where we are getting info from Claudia's diaries that fade into a scene, the show has Claudia's voice-over narrating at some point during the beginning of the scene, to show that what is being shown is from Claudia's POV. However, that does not happen with the train scene. The only voice-over we have is Louis' voice-over at the beginning of the scene, and that is it.
Levadopa, the drug infusion Armand arranged for Dr. Fareed to give to Daniel, is not given to someone who has Parkinson's via an IV drip infusion unless the person is in a hospital, or maybe when they are in the very late stages of the condition. And if Daniel had late-stage Parkinson's, he wouldn't have been walking around the way he was, never mind how he wouldn't have been in Dubai in the first place either. Levadopa can not only make someone drowsy, but also cause confusion, too.
In Episode 2x05, back in 1973, when Louis is talking about the moment when Claudia left him on the bench to go and catch the train, his emotions about that moment are a 180 from the emotions he shows when talking about that same moment in 2022. In 1973, thinking about that moment had Louis breaking down, which was the moment the whole interview went sideways, and all ended with Louis trying to end his life. In 2022, however, Louis speaks of the moment in a completely emotionally detached way.
In 1973, Daniel, even though he was high on coke and ludes, was still awake and engaged enough to ask questions and give his opinion during that moment. In 2022, in contrast, Daniel was doped up on a medication he shouldn't have been given outside of a hospital, which had him falling asleep as Louis was talking about that moment.
And finally, in 1973, Armand listened to all the tapes of the first interview Louis did with Daniel twice. Meaning Armand would very well have known at exactly which point, and which topic, Louis and Daniel had been talking about when the interview went sideways, and then had Louis almost trying to take his own life.
So there we go. There was no diary entry from Claudia about the train scene. Daniel was drugged and fell asleep at some point when Louis was talking about it in 2022, in contrast to 1973. And the emotional difference between 1973 and 2022 when Louis was talking about it all was a full 180 between the two time periods.
