WoWJutsu was once the number one guild ranking website, tracking progression, boss kills and all of that great stuff. Unfortunately, it hasn't kept up with the times. WoWJutsu's tracking relies on the Armory, crawling the whole thing and using gear that characters have equipped to determine progress. In order for your guild's Malygos kill to be marked down, members of your guild need to have Malygos drops on their Armory profile. This is the only way, as far as I know, that WoWJutsu will list your kill.
What does that mean? Well, it implies that guild progression isn't tracked properly at all. The first guild on a server to clear all of the content can easily come in third or fourth or twelfth on the ranking list. If your armory page doesn't update right away, that alone is going to throw your guild's progression record off. As minor as it may seem, it actually has some bad side effects, specifically when it comes to recruitment. If you claim your guild has cleared the hardest content in the game when you're looking for applicants, and people check WoWJutsu to make sure you're not making false claims... well, WoWJutsu's inaccuracies could imply that you're lying, when you're not at all. It's damaging.