@jherron The information is split in two different tables. Host information and MAC information. So you need to commands to clean that host’s information from the database:
mysql> DELETE FROM hostMAC WHERE hmHostID = 1272;
...
mysql> DELETE FROM hosts WHERE hostID = 1272;
...
But I still wonder why we only see one entry while FOG seems to find duplicates. Would you be keen enough to add some more error output to the PHP code so we see which MAC it sees as duplicated? If yes, I should be able to help you with the code. Let me know.