When draft comments are edited and saved as public comments at the same time, review history gets updated with the old (draft) comment text.
To reproduce:

• create draft comment in review, e.g. "draft comment"
• click edit, change the comment text (e.g. "public comment"), click "Comment" rather than "Keep as Draft" to have the comment updated and published at the same time
• expect to see updated comment text on review page
• but when looking into Review History, you would notice "added comment" action with old comment test (i.e. "draft comment" rather than "public comment") - that's wrong.