literally yes it does. it would not be in the game if they did not put it in the game
They didn't put in the game.
They put it in for a very specific error in a very specific tool in the development kit. The Development Kit was handed over to Hired Gun Studio who made the PC port. We can absolutely confirm that they modified the source code because Microsoft requested that the Development Kit be "locked down", and so a lot of features and functions of the H2V editor are locked and cannot be opened.
Hired Gun should have replaced or deleted the image when compiling the final executables, but instead they left it in. The forget up is not with Bungie, since Bungie weren't the ones to release the editing kit and never intended for that image to go public.
EDIT: Since Hired Gun Studio was owned and run within Microsoft (and dissolved after 2007, with their only project being Halo 2 Vista), I think you can easily guess who was fired.