Thanks for the feedback and compliment!
If you want to try again: after the cube puzzle it should tell you to toot the horn but it's possible some other sound effect was playing so that you couldn't hear the instructions. Regarding the clipboard glitch, we definitely didn't test that case. If you end up outside the train, you can usually move around until you are falling, then it will fade to black and teleport you back inside.
We definitely needed some more time for QA before release hehe ;)