When attacking Russia for a specific thing, bringing up the misdeeds of the US are a distraction, and "whataboutism".
When comparing the morality of the two nations (or criticising the "world police" status of the US as hypocritical) recalling American misdeeds is appropriate.
In the case the post was "what a corrupt state", attacking character of Russia generally, hence it's appropriate. It's worth pointing out that OJ Simpson published a book "If I did it", which could be seen as morally unacceptable too - but then there would be a difference between "that's terrible" and "America is terrible".
When comparing the morality of the two nations (or criticising the "world police" status of the US as hypocritical) recalling American misdeeds is appropriate.
In the case the post was "what a corrupt state", attacking character of Russia generally, hence it's appropriate. It's worth pointing out that OJ Simpson published a book "If I did it", which could be seen as morally unacceptable too - but then there would be a difference between "that's terrible" and "America is terrible".