Ok, the problem has to do with trackbacks - apparently they are included in the comment count for these two items:
$macros.CommentUrl($post, "%{anchor='comment_list'}")
$post.CommentCount
I modified my theme a bit to display the trackbacks too (per this link), but I'd really rather trackbacks had their own seperate count and were not included in the Comment Count. Before displaying them on my page, I was very confused why the count would denote many more comments than were actually on the page.
Additionally, deleting the trackbacks via the Graffiti Admin does NOT remove them from the count.