Word for being biased "towards the other direction"?

Solution 1:

He is speaking against his interest. In legalese, you'll also hear against interest with no possessive – for example, a declaration against interest is a statement that is (as Wikipedia puts it) “so prejudicial to the person making it that she would not have made the statement unless she believed the statement was true” – but in normal-person English I think the version with the possessive is superior.

Solution 2:

I would say that Smith is objective. He is answering the question objectively; that is, he is not letting his personal interest in the matter sway his opinion.

objective (adj.) based only on facts and not influenced by personal feelings or beliefs; undistorted by emotion or personal bias.

interest (n.) a connection with something that influences your attitude or behavior because you can gain an advantage from it

^{(Definitions supplied from OneLook.com)}

Solution 3:

If Smith is already paid a low wage, for him to approve of having his wage lowered further to allow another (albeit important) public servant to get a pay increase, I would say that he is:

A) radically unbiased B) highly altruistic C) off his nut