Password-Lacking Marine

In the Halo 3 level "Crow's Nest", there is a marine at the end of the first long curved corridor. There is a funny exchange of words between this marine and someone behind a door. It goes like this:

Marine: Hey, open up!

Voice: Password, please.

Marine: You gotta be kidding me, what password?

Voice: The password so we don't let any Brutes in.

Marine: Do I sound like a Brute to you?

Voice: Well, you could be held prisoner by Brutes.

Marine: If I was held prisoner by Brutes, they could force me to tell you the password.

[Brief pause]

Voice: Well, now I'm definitely not gonna let you in!

Marine: We need ammo!

Voice: Why don't you ask your Brute buddies for ammo, then.

After this, the marine repeatedly knocks on the door. This can be found on any difficulty. Interesting to note is that the marine's voice sounds like Tucker's from Red vs Blue.