The article is correct; at least they are honest that the Bible condones slavery ... but then they are willing to defend that, as the Bible must be inerrant.
Most fundamentalists steer a middle ground between embracing slavery and the liberal position of ignoring it; they simply claim the slavery the Bible talks about is different from modern slavery simply because in the Roman and Greek worlds it was slightly less than impossible for a few slaves to become free, and there were some forms of slavery that were allegedly more like indentured servitude. That somehow because it was structured a little differently than it was in the American South it was somehow okay at least "back in those days".
The fundamental problem of course is that some particular religion does not decide what is (im)moral / (un)acceptable behavior; society does, and the church is obligated to comply or suffer the consequences. Society has evolved on this issue and the church has no choice but to drag itself, kicking and screaming, into the modern world.