I don't get it why they would give you freeroll when if you win they won't allow you to withdraw?
It's not the honest way for promoting the betting site as it's just making the users go waste their time. Now it's going to ruin their reputation instead. No matter how small or big the amount he won, it deserves to be sent to him.
The business doesn't really expect that someone with a free roll is going to hit it big so they have to find a way to make the winner miserable by making it look like the player cheated the system. I do agree that the player has to receive the win, withholding makes the site a bitter loser in the face of things.