I suspect the surrender code was ported over from an abandoned Spartan expansion pack to R:TW.

"The enemy sends his terms. We are outnumbered 99 to 1, I sugg-"

"Blast them! We will return home with our shields or upon them!"

"Sir, we don't have shie-"

"WHEN I WANT YOUR OPINION, I'LL STICK MY FOOT IN YOUR REAR AND DICTATE IT TO YOU, SPARTAN!"