Yeah I strongly suspect that there's something in the GTFS spec that I'm missing that's resulting in some vehicle journeys not being added to the timetable. This would also explain why it completely fails to find routes on the return trips for some of the examples. I'm still pretty stoked about it and hopeful I'll get the bugs ironed out. :)

edit: also if you look at the Berlin to Barcelona trip you'll see a bus, which makes no sense to me whatsoever, so I suspect that some of the high speed rail trips didn't make it from the GTFS feed into the packed timetable that I'm serving itineraries from.