someone edited my answer with two distinct changes, one of which was good and one bad. (The first improved the markup of the answer, the second introduced a bug in the code)
Could the reviewers be given the option to approve(or rollback) separate hunks of an edit?
...Or even better: could the post author be given this option?
I reverted the bad change through a new edit, but it would have felt better to rollback the bad hunk with a comment to the editor.