Distriator has a very easy way to curtail abuse... If someone is "cheating" they their whitelisted status gets removed. No longer will they get kick backs, nor upvotes from them.
So... can it happen? Will it happen? Sure. Impossible that humans will behave all the time. But unlike downvoting, drama, insults and war. All you gotta do is delist them from their system. (they don't even need to know it happened).