Tigus, this one is weird.
It isn't like Seven Dead or Thirteen at Dinner or Mystery in White at all. This one is along the more silly, and dare I say, even stupid lines of Farjeon's first Ben, the Tramp mystery.
I hope there is a twist that changes my impression, but so far, our MC's actions seem entirely implausible, and so is the dialogue. Don't even get me started on the weird pencil-menu-napkin exchange on the train.
And the police are not much better, ... unless this turns into an early version of North by Northwest.