As I have noticed these days, when the ICO hasnt finished yet and the sale was still on going, the bounty tokens has already been distributed and also unlocked they sell it immediately on forkdelta or etherdelta for a much lower that ICO price, in which it could greatly disturb the sales in tokens. As for you the investor on that token, would you panic when you see that the tokens you own already selling at much lower price?
As far as i know the bounty token will be distributed to the participants after all of investors will have received their tokens and the token has already listed on the exchange site. There is no reason to distributed the bounty token before all of the distribution to the investors will be completed. I never see that