BBC interviews are always the worst. The sheer smugness and arrogance of their interviewers is insufferable, they act not only like they think they're smarter and morally superior but as if they were conducting an interrogation of a criminal. The only way to respond to these assholes is like daddy Lukashenka did:
This interview is so iconic, I do find his responses refreshing. When it comes to Andrei Klein, I am also astounded at just how patient he was. I do not know how he was able to keep such a calm demeanour and answer her accusations (framed as questions). According to the comments thats just how Russian diplomats are, but some say she would’ve had a harder with Maria Zakharova (I don't know her that well, but maybe they’re right).
I found a YouTube link in your post. Here are links to the same video on alternative frontends that protect your privacy: