which looks like a 32 bit word swap but the byteswap involved is hidden
If this was not done right you would not have gotten the 50.00 btc at the end.
If you reverse the hash from cpuminer, the nibbles in each word are reversed. You would need to reverse the nibbles in each word, as well, in order to get the right hash. I guess the hash calculated is still correct, but it makes for bad surprises checking the minerd's output, getting hashes that seem to hit the target but actually don't.