I was looking a deleted answer (the link is for 10k users or moderators) for which there was a comment.
When I clicked on "show 1 more comment," the comment was not shown.
Who has stolen the comment?
The ♦ "show deleted comments" button reports that one comment was deleted by the user (nico) about 1 minute after being created. It is entirely possible that this is simply a denormalized counter that was misreporting as "1" instead of "0" (for the number of active comments) - perhaps some old glitch due to the post being deleted.
Edit: there is a second comment that was deleted more recently (the comment was obsolete) - I'll check if there is a glith in the admin tools (i.e. not resetting that counter)
Isn’t there a possibility of user may delete the comment at the same time where you try to view that. If so you might see there is a comment which actually not there.