I could not quite put my finger on the reason why Russian speech feels somewhat off in this, but I think I finally got it. The sentences are way too simple and short, so the border patrol guys end up sounding more like robots rather than humans. Although, it probably doesn't matter all that much. I still feel the amount of research and effort Noda-sensei puts into his manga is amazing :з
The misused letters though are weird as hell. It should be so easy to check, I really don't get how this Eugenio dude missed it twice already.