Ah thanks for this hint. I understand the problem now – it’s because we’ve made it possible to reply to a subsequent post despite everything still being displayed chronologically in our topics.
I’ll likely remove the counter in each post, since it will not prove to be useful – crawled topics have posts that are loaded chronologically so nesting replies would not work here. Our “Reply” button also has a bit of magic going on (a reply to the last post is the same as replying to the topic).