If you look at the last image in the post, you will see that "expert" votes have little correlation with points.
In this image, two projects mention being upvoted by an "expert", and the two are in the top 10 indeed.
Overall, I find that the evidence fails to convey the point, I may be wrong and the case is strong but right now, I don't think it's convincing that anything shady is happening.
I'm not surprised that the ultimate choice of giving out money is closely guarded, because the very little amount of voting happening makes it very sensible to fraud. (When a photo of an egg can get 20 million likes on twitter, basing a contest on handfuls of votes would seem a bit...naive.)