He doesn't address their accusations; at this point, he doesn't believe it will do him any good. They've made up their minds, if they're willing to kill the other members of his team for it, and he values what little life he's got left in him. Slowly, he raises his hands, gesturing his surrender and acceptance of Rey's terms.

Instead of silently accepting that he's essentially under her guard now, though, he pipes up to question her in a rough voice, "What do you want?" She could have killed him, but she didn't. If that were still their goal, he'd already be dead: instead, they're both talking. That's progress. (Then again, they could have let the monsters devour them, as well.) With any luck, they need him for something, and he can use it to get back to the rest of his people—or whoever's left.