Are you saying that Freebitco.in is manipulating the server seed?
This is why I don't understand what they are going on about. Like every other provably fair site we give you the hash of the server seed before the roll. Then after the roll, we reveal the server seed and you can check it against that hash. The client seed you are free to change, use static or random.
Edit: I should have said "every other provably fair site
that I've used".