The mudlib is called "open source"...... anyone can use it. (If I'm not mistaken)
And yeah, the Tolkien Estate is pretty anal about using his material, so.... it was obviously just a mistake on someone's part, one of those things which slips through the cracks, but hopefully it will be changed. Maybe to "Horn of the Earls" which has sorta the same ring without being copyrighted (I hope
)