I'll check the queries, but please note that the community is also capable of dismissing flags, by hammering a post into submission. Indeed, flags on posts that are self-deleted are generally dismissed too. Meaning: it is entirely possible that the remainder are either the OP deleting a post that raised a lot of flags, or the community flagging it enough times (spam or offensive) such that it was deleted automatically.
Edit: the total number is the number created, not those that were specifically handled by moderators. Anything flagged but subsequently removed by either the poster, or mob-rule, will not be reflected in the numbers on the right.
Additional; the above was incomplete (although the two reasons provided are valid reasons for differences). It turns out that the 4 votes on skeptics.SE are due to comments. Comments are given a very light touch, and are not currently formally tied to the moderator who marks them as completed, however I can reveal that 4 comments were deleted by Fabian (your good self) today between 07:50 and 07:51 UTC today. So "comments" was the explanation in this case.
I think querying this could be bit expensive for the main table; however, I suspect we could display this on the "more detail...", so next time, clicking into a few users should reveal all. I believe we already display comment edits by moderators - it is just a cased of adding comment deletes.
Changes that have been made as a result of this meta question:
- the "Cmnts Deleted" column was... specious (ok, just plain wrong) - it is fixed
- there is now greater visibility of comment deletes on a post's moderation history
- there is now greater visibility of comment deletes on a moderators (recent) history