So I tried finding these guys yesterday, and it worked. There is two, and they both show up in the only two group of allies you get on that TotS (or at least before you get on the falcon).
I got distracted with the dialogue, and forgot to look for the QTA. Here's some random stuff I heard while staring at them and switching weapons quickly, most of it may have no purpose. And a few aren't exactly word-for-word.
"To think that I could be on Sigma oh-4 right now, nothing but blue skies, beaches, and college girls, heh heh"
"So you spartans never die huh? Maybe some of that will rub of on me... maybe..."*
"Maybe some day I can be a giant robot who stares"
"What, are you supposed to be the strong and silent type or something"
"Can I dual-wield one of these things?"
"My trigger finger hurts already" (this was from switching weapons really fast with another Trooper)
"Takin' Five, Lieutenant?" (From the Marine with the supposive QTA)
"I bet under that helmet you have long, flowing locks. Please tell me I'm right, I'm right aren't I? I'm right."
And then I heard
the Spartan wish one</Random Dialogue>
*Other than that, they didn't seem to do anything special or act abnormally.
I was playing on Normal with 3 Silver Skulls on. DNF.
