Here's a representative example of the guy's speech, from two years ago. No way to find the ad that I saw:
The guy, as Google confirms, is originally from Belarus, which he left at the age of nine and continued his education in Sweden.
Out of the signs that I can recognize it is primarily his consonants, specifically that he still retains the opposition between the soft and the hard consonants: a very hard /t/ in "it is", an excessively palatalized /t'/ in "seventeen", a strongly palatalized /s'/ in "see", a hard unaspirated /k/ in "bitcoin" and so on. I have a feeling that his intonation as a whole is a much stronger marker, but I have no formal way of thinking about it and describing it.