There is no way Sherlock couldn't solve such a simple case fast on his own! it was so obvious the suspect is most likely to be a train crew member the second a bottle of Whiskey was discovered in the locked cabin wand the key was missing. At least this is what I thought and I’m no genius. and the footprints all over the train! analyzing footprints is Sherlock speciality how can he not realize just right after checking the cabin. And the suspect went to the washroom to clean the blood. again obviously! because that’s where Watson got blood on his clothes. and the lie was obvious too “i cut myself during work while I was wearing the gloves” oh so this is way you washed the gloves and there is no cuts on them? can you be more obvious! I don’t care too much about historical accuracy but I can’ forgive naive Sherlock. This is a comedy version. That’s must be it!!!