I would like to draw your attention to the incorrect translation of Oleg Tinkov's original phrase.
The word "doubtful" is used to refer to people who are in doubt (see Doubtful in oxford dictionary), whereas, what Oleg originally meant can be translated as "questionable", that is, something that you are in doubts about, i.e., something you question (see Questionable in oxford dictionary).
I would like to draw your attention to the incorrect translation of Oleg Tinkov's original phrase.
The word "doubtful" is used to refer to people who are in doubt (see Doubtful in oxford dictionary), whereas, what Oleg originally meant can be translated as "questionable", that is, something that you are in doubts about, i.e., something you question (see Questionable in oxford dictionary).