Blog: postCommentCount displays incorrect number of comments

While testing during development, I posted, approved then deleted a blog comment on an imported-from-WordPress blog post. However, I’ve just noticed that the postCommentCount for that now live blog post is off by +1.

It would seem like my postCommentCount was permanently increased — maybe because the comment was approved before it was deleted?

What would be the safest way to fix this number? I’m comfortable just changing the number in the db, if that won't have any undesirable repercussions, but would love to know if there were a less hacky way to get the postCommentCount for this particular post corrected.