So they didn't totally abandon slavery.
Well it was the initial major step, while independence movements in India, South Africa, et al. followed later. Also, while Gandhi followed Christian political principles, he himself was Hindu - and I am not certain it’s fair to cast Britain with the full weight of historical Hindu vs. Muslim hostilities.
Of course I am not trying to dispute British guilt, but rather the hypocritical grounds on which Ms. Zakharova is speaking from. I think the British are doing a better job of wrestling and reconciling with their past. Some of the most moving World War I/II memorial services as of late have been organized by the Church of England and parties even from former enemy countries like Turkey (Ottoman Empire) are invited to attend. They can be viewed on youtube.
In person though, I have been to Russia’s “Victory” parades. They tend to be more self-serving and propagandistic. Glorifying of war in the same spirit that led to such wars in the 1st place.