That question first and foremost tests English reading abilities. Many mathematically gifted non-native speakers (and indeed native speakers) would miss-understand the "different".
No, but there might be reason to doubt the translation on the basis that the intersection of the skillsets "fluent in Russian" and "total command of the relevant computer science material" might not have many people.
For a fair comparison, the translator would have to fully appreciate the relevant connotation of every significant word like "different" in every question, and successfully convey the same in Russian. You couldn't just go to a regular translation service and get a good result.
A lot of computer-related words in Russian are borrowed with small modifications from English (or from where English took them). Nobody says "electronnaya vychislitel'naya mashina" anymore, they say "computer". Same for file, register, class, object, compiler (kompilyator), algorithm... It happens that tutorials for some computer-related subjects - especially some niche ones - are available only in English. It sometimes help that programming languages use English language base for keywords, so there is less confusion with Russian words.
Doubting that the translation caused some discrepancy isn't unreasonable. Technical and academic works are notoriously difficult to translate, and it's entirely possible that even though "different" was stressed, certain languages lost the distinction, whereas if the word had been "unique" the distinction would have remained.
Although I have no faith in a multiple choice test as a predictor of CS knowledge anyway. That is just a horrible test format anyway.