When the fake railway personnel are talking about Emily and Cal, there is a warning on the wall behind: Non-Smoking Station (in Germans and in English). The translation is correct, but this warning belongs to a railway station on the ground, and not to an interior of a railway coach.
When Crown goes to Thompson to get her into the conference room, the actress' accent is heard before her 'American accent' kicks in.
The railway station, where the train was stopped, is in fact 50 km north from Sofia, called Bov (note: the area surrounding became independent location under the name of Gara Bov, but this fact has no effect on the name of the railway station: Bov). It was mentioned by Emily and Cal as Schönberg (which means beautiful mountain in German), but on the station building stands by mistake Schunberg.