Oh, I don't know then, but my guess is that if this is not a bug (and I don't know whether it is one), then maybe it's because you beat the slavers caravan, the slavers don't want to deal with you, so your quest will probably evolve slightly differently. I also think that if this is true, there will be something to do at the hideout, regardless, and it's fortunately implemented in the next release, so we will have to wait and see.