While Rath is waiting at the train station the male prostitute appears to first approach him twice from different camera angles.
The two soviet GPU agents arrested by Rath for their participation in the massacre at the so called "Red Fortess" had Tokarev cal. 7.62 pistols. While the episode is set in 1929 the Tokarev pistol was not produced before 1931. Real soviet agents would have used their standard Nagant revolvers or contemporary pistols of western origin.