You don't know that he didn't. He hasn't yet revealed which portion of the Sartre text he claims hashes to the same hash. That was the point of the thread I created which Gmaxwell has apparently sent to the ether (against forum rules).
And you really believe that the double hash of some Sartre document just happens to be identical to the hash of the first (or one of the first) txs in the blockchain?
Am guessing you have a very strong belief in the tooth fairy as well.

Again - if he wanted to demonstrate that the double hashes match that would be trivial to show (but of course again he won't do that now will he).
It should be noted that not a single SHA256 collision has been found to date (so CW's claims of world's firsts and amazing achievements just keep on piling up).