While Jean Claude Tremblay backed tracked a bit on the certainty of his conclusion, his conclusion remained the same. In his post on his own blog where he backtracks, he concludes: "In my humble opinion, what I see about how the PDF is built does not prove any unusual falsification. If there was tampering, we must look elsewhere and not how the PDF was constructed."
Jean Claude Tremblay
Further, he provides a link to another article here where "this process was explained by other experts better than [him]".