Something that was brought to my attention a bit ago is that images can suddenly disappear from my uploads list while neither being added to my deleted posts list, nor were they nuked. post #2734521 and post #2734522 both still exist, and I'm still listed as the first tag editor; because the images were directly replaced with superior versions instead of being deleted in favor of a new post, the staff member who replaced them got them added to their uploads.
I feel like it would be fair to treat this as a deleted post, as would happen if it were deleted in favor of a differently numbered post, and a "zombie" deletion show up in the original uploader's list. Uploading an inferior copy of an image is still uploading an inferior copy, after all, and this would allow original posters to still find their posts through their userpage (via the Deleted Posts link). The alternative would be to just not have the replacer take the uploader status.