Here is a screenshot, that will explain the problem:
This may be reproduced as follows:
Vote down on an answer and give a comment.
Wait for post to be edited and answerer to give a comment.
In a different tab, undo the downvote and give an upvote (for fixing issue with post, for instance).
Click on the "Show one more comment" link in the comments section.
Observe both vote buttons orange and new comments displayed.