I think ETHFinex have made a deal that will favor them. I bet they did not take any risks there but I wouldn't call it being stuck on the tokens. If they believe in the project they got a big share.
They took a little risk since they are the first project to run token sale on their website but we wont know what agreement they made about unsold tokens.
Maybe they can release the agreement some detailed explanatory between ethfinex and the dusk team in the near future.