In Brazil I doubt you would win anything by meaning the way you write it is copyrighted. Unless the one qho used the mechanics did not quote the source and gave him the credit anyway.
they forgot to put it in, simply put. But sincee you don't want to end up using unique IP of the setting that is hard to separate of the system mechanics he suggests nyone wanting to publish what they have made in the book to mail them and get a talk over it, to make sure you don't get into trouble.