No, it's really not. Once they said "litmus test", that makes it clear they're doing it intentionally, not as a logical fallacy - it's gauging bias on common topics, which is relevant to a discussion on bias and propaganda. It's not a series of seemingly-related non-sequiturs that have nothing to do with the topic at hand.
I'd love to be proven wrong here - how is what they brought up not relevant to the topic of bias and propaganda, especially wrt the west?
Oh, it's definitely ad-hominem, that I agree with - they were literally testing your biases, as they stated. I don't think it's whataboutism, just ad hominem, actually. They're accusing you of being as biased as anyone else, then asking a shibboleth to prove their point - the whole premise is ad hominem at that point. I think the differentiating factor is that the questions were about your beliefs, not about the actual events they brought up.