There was a lot of controversy before the actual patch was released about the leaked patch and whether it was identical to the real patch. WernerSobe, if I recall correctly, saying that it "WAS" the real patch, and in fact announcing that the md5 checksum matched. John Channing, however, gently cautioned (ok, he authoritatively announced) that it was not the real patch.
Now that the controversy, in which I declined to participate, is over, I can announce that the md5 checksum of the leaked patch, SilentHunter4Patch1.3.exe is 557be67b259a6f073d02502a7c459f8e. The md5 checksum of the real patch, silent_hunter_4_1.3.exe is 200920d06ab324cc272b4dd68424d849. Whether those two are the same or not is up to you to judge.
Pass Mr. Channing a cigar and remember well for next time.