[rdtsc]

> It would be very weird for anyone to make assumptions about their identity based on broken english.

They could be haven trying to disguise themselves, maybe fearing a grammatical analysis or somehow exposing some fingerprint in how they construct sentences.

And as throwaway claimed, if you speak both English and Russian (I do), and have heard many others who speak both English and Russian for a many years you start to pick up patterns and understand when someone is speaking with a fake-make-it-sound-Russian style.