I think they wanted an early review so that Sony could know the quality of this and if it was worth marketing. There was proof in the beta, but you can't be too careful. They didn't want another Haze on their hands, and I think this is the final proof necessary to show that it is not going the way of Haze (which got 2.5/5 from OPM)
They gave it to OPM because OPM always gets early reviews, and because they don't nitpick. IGN doesn't nitpick either, but maybe they wanted a PS exclusive reviewer.