Well, since no one has bothered to check, here is a detailed comparison of the two files.
You can see the difference on the first screenshot. The version from the Extras patch has byte 00 occupy the offset 1A0B, while hellrazor's version has byte 19 at this offset. This byte corresponds to the "ground" value of the 17th tile in the 16th row on the 2nd level of the map. With the MapView tool it can be seen that the ground is indeed missing in this particular tile in the Extras version of the map - which is exactly the point from where I can spot targets below and shoot at them (of course, the aliens have this advantage most of the time, but I've run a few tests in debug mode as well).
There is also an extra byte at the end of the file in hellrazor's version, making it 9604 bytes long, which is one byte longer than the intended value of 9603 (because 3 bytes in the beginning specify the dimensions of the map and the remaining part is composed of 4-byte records). I guess this extra byte is simply ignored by OpenXcom, so it doesn't really make much difference - although it makes it possible to simply compare how long the files are to refute the claim that hellrazor's version is the one which comes with the universal patch (because it is not).
Perhaps there is a new version of the patch somewhere which is not that easy to find? Similar to how "1.0" is posted as the latest release on the main page and the nightlies are a bit harder to discover for the uninitiated.