That's exactly my point. The introduction of a thumbs down graphic is confusing, providing the potential to think 'How the hell did I manage to give him/her a thumb down?'
Even if you are unliking a post, and you want the thumb to symbolise a functionality of a link rather than a current rating of a post, a thumb down graphic is misleading as it suggests you are giving it a thumbs down (dislike) rather than simply returning it to a neutral rating.
The Daily Mail website has it sussed with its hollowed green arrows (and filled in green arrow for when you've rated a post yourself):
But Bozza didn't design this modification, if you think it could be done better go and find the person who made the modification and suggest the changes to him, there is nothing anyone here can do about it.