Ah yes, I forgot to mention Yulia Stepanova, same things apply to her.
To be completely honest, the biggest evidence against the Russian officials so far is their inaction. People expect Mr. Mutko and his team to bash those who accuse them with all possible means and to sue Mr. McLaren for defamation. I don't know if it's just their incompetence, or there are deeper reasons for this.
Actually, its pointless.
For example, they will sue. If they sue in Russia, you know what people will say, right?
if they sue in an international court, guess what will happen.
There is a russian saying "to prove one is not a camel", and i suppose this is one of those cases