Ok.. with you saying that the owners would be responsible for the payout your version makes sense.
Still .. are you sure its actually that way?
Because that could mean that in a bad scenario (some whale *loses a lot on the site ) they would be liable to huge payouts because of the leverage?
Either that or they are setting the max-bet limit really low so that swings above some few % are mathematicaly extremly unlikely.
edit: *i meant lose instead of wins