How do we know that the Revision3 content was legal? Because they (Revision3) say it was? I don't buy it. MediaDefender isn't stupid; they found illegal content and shut it down. The reason there will not be any investigation is because Revision3 cannot allow an investigation to occur, lest they be found guilty of hosting illegal torrents.
Here in the US we have one little legal principle known as "innocent until proven guilty". Perhaps you've heard of it, perhaps not. Essentially, it's what keeps the justice system from being a Jump to Conclusions mat.