Last night, March 13th, Death and Taxes of the US realm Korgath, defeated The Lurker Below. Though they claim this is not the first time that they've killed him - hence showing two sets of loot - he was also killed last week.
Apparently there's a bit of a rivalry brewing between Death and Taxes and the EU guild Nihilum, as you can see from the quote below:
Actually we killed it last week too, hence the double loot in the pic, but we didn't know whether it was a trash mob or an actual boss, we were waiting for a confirmation from Europe. Apparently they seem unable to tell us so we decided to post anyway.
Congratulations on the kill D&T - we here at Curse are looking forward to your future kills!

Comments
After doing a bit of research(and the fact that D&T killed him last week as well, before any hotfixes were applied), I'm going to leave this as-is with the World First Kill title. If anyone has objections, please feel free to post them, but as it stands they defeated the encounter while it was bugged and had a chance to despawn, evade, etc. as well.
Kiltek: Nihilum killed The Lurker Below yesterday, so I'm sure he was in as much of a working order there as on US servers. :)
Iamjack: It's a running joke - Nihilum compared Fathom Lord Karathress to a trash mob in Serpenshrine Cavern, to try to debunk Death and Taxes' World First Kill of that encounter, so D&T kind of carried that over to this kill as well. ;)
no they know its a real boss. The whole reason for the comment is that nihilum have been like "was this even a boss?!" on all bosses this far in serpentshrine.
I guess he would be easy as hell.
How come they don't know if it is a trash mob or an actual boss?
Basically, this shouldn't be shown as a World First.
Why? Because the EU version of this boss is completely bugged, im not sure on the details but I believe it's something to do with the spawning mechanism.
Thus, this should be displayed as US First, and when EU get a kill, it should be called an EU first.
D&T is defo on it's way to become unreachable on world firsts. Unless they get stuck somewhere ofc.
Job well done D&T, keep those world firsts coming! Show the world the power of the alliance.
It's certainly likely AirForceElite.
Must be a clown-worthy fight, as far as relative difficulty of bosses goes.
they dont know wether it was a boss or thrash mob? what are they newbs or something? would a thrash mob have its own web page on wowwiki.com?
GZ! whoho im first