You’re on lemmy.world, which has been defederated from hexbear.net for ages. So yeah, somebody on your instance would have to go there so see their content, because your admin essentially blocked them for you. Anecdotally, I saw them on lemm.ee’s All fairly frequently before I blocked them, and I still see their comments on posts on other instances fairly frequently.

Plus, more recently hexbear has had to change domains and apparently because of this federation with hexbear isn’t working at all for anybody at the moment