Stocks have always been allowed and been used for picture manipulating. Every entry here has been some kind of image manipulation, be it stock images or renders found on internet. Saying that stocks can/should not be used for manipulation, but A can use a render which was made by B using a stock made by C, on a stock made by E and then it would be legit is only complicating things for the sake of it. You are downloading work of two or probably three people to add you own in this case instead of one. It doesn't really make the work more legit by itself.
Now to image manipulation: Is there a definite point where we can say the image has now been changed enough to claim a different work? Not really. Some will argue that changing even one pixel is manipulation, others would say no matter how unrecognizable the end result is, it's still ripping others work. We cannot reject a stock for the reason that it was too good either. So, as long as the stock itself was not created to be a signature and technically the member made one out of it, the submission is acceptable.
If someone believes that image was not manipulated enough they can report it to the host and s/he will decide whether it's edited enough to qualify as signature or not. The fifth entry was deemed qualified. There were subtle changes in the image and text blended in really well.
However the fifth contestant has requested to pull back his entry, so in case the entry wins the award will go to second winner.
Result will be announced shortly. That would be all.