According to Marc Gravell's comment on the answer to this question, a regular delete of an account also deletes anything that is negatively voted. However, this question has two answers from deleted accounts that are downvoted but not deleted.
How does that happen? Is it a bug? Or were the downvotes accumulated after the accounts were deleted? And if it was after they were deleted, is there any mechanism for auto-deleting those negative posts (perhaps 7 days after it gets negatively voted)...or should there be? Or should I just flag those for moderator deletion?