Hollow Rock/missing Texture - Phobos (Roche Mission)

[Warepig]

Hey, was doing the exterminate mission in Phobos called Roche and I came across an invisible wall blocking the stairwell.
Upon further investigation by climbing a nearby ledge, I discovered there was actually a rock wall there, but half of the texture was missing.

 

Screenshots below;
http://gyazo.com/e91bdb7fda95b4b358fe4d8756b490e8

From a different angle to show it's see through on the end I first approached it by.

http://gyazo.com/2d33fecef3782f51d00b0f86fad2a22a