Problem/Bug Nether Generation in The End

Someone brought this to my attention and I found it quite interesting, so I was wondering if anyone knew the cause of this, or if anyone else has experienced this strange occurrence.

On first inspection it seemed like someone was just simply building staircases using netherrack in The End world, however as I flew around more, it became apparent this was not the case. We have LogBlock installed on the server, and it shows that every single one of these netherrack blocks were broken by a player, but never placed.

It then hit me that it's highly possible that these blocks once existed in the Nether world, and when broken, were then generated into The End world. It explains a lot of the shapes you'll see in a moment, for example some look like staircases someone would dig to reach the surface, and others looks like a pillar going directly down.

I've uploaded some pictures to an imgur album, if you want to check them out.
http://imgur.com/RGPxPPC,DOylfup,e2lhw1Y,9sKGJwP,IRFDJnQ,T0ZDh30,0VlF2nq,ErrGxUQ,HFszmM9,OHzFYkN#0

 

@xDeeKay Thats so weird... Could it have been a plugin that you have installed?

 

@nverdier I don't have any plugins installed that effect terrain generation, so I'm not sure if that's the issue. However it probably doesn't help I'm still using an old 1.8 build, so I might update that and see if the problem persists.

 

@xDeeKay Yeah, that's probably the problem.

 

@timtower I'm running CraftBukkit, sir.

 

@timtower You'd be right there, I don't recall them doing anything lately.