The threading seems to be displaying wrong in the comments, where a reply is being shown as a sibling instead of a child of the parent comment (see screenshot). Specifically, comment #23682661, which asks if an AC donates to Wikipedia, has a reply (comment #23684459) which quotes it, but appears as a sibling. This is the third time I've noticed something like that, and it seems extremely unlikely that the person is replying to the wrong comment.
broken threading example