You mean the Radio? If it was a codec it would just be nanomachines so they wouldn't be able to remove it.
The Radio, maybe it was like MG2 when Holly gets captured but hides her transmitter? Maybe? But they couldn't change the 3D model here? Or maybe they realized he didn't really have any valuable information, or they can give him false information and make him report that? Any of those could work.
From a gameplay perspective is to have the whole Sorrow passcode method to escape (And The Guy Savage Easter Egg).