ZOMG! Noob Alert! I am almost certain I am the most Experienced Modder for any of the 3 games across all platforms on these forums. There certainly was no 'weird' or 'ghost' files within the assets of Lockout.map. :/ I can confirm that, HANDS DOWN.
The idea of 'The ghost of Lockout' came from a very rare event in witch some MASSIVE lag took place when a person was joining another person's game. The video of 'The Ghost' can be found
HERE. The video was released years ago over at High Impact Halo, I can even recall posting in the video makers thread :/.
Its only an extremely bad connection to the host. Now stop fighting over how there are secret files that makes this ub0r ghost come out and kill everyone, or how your friend got Bungie to tell him there was some secret ghost :/.
-Doom