The guys are freaking out because they can't see what's going on inside the vehicle. They're worried that the guy is going to run away, so they're going to have to shoot him. They don't know how to do it, but they've got a plan: they'll barricade the outside of the vehicle, so the guy won't escape. They hear gunshots coming from the inside of the car, and they think it's a war going on in the car. They can hear the gunshots from inside the car too, but it'll take some time for them to figure out who's shooting at them. They wonder if this is the same guy they killed in the previous scene, or if the guy's dead already. They need their eyes, they say, because they saw something in the vehicle that looked like it contained a bunch of different types of cone cells. It's like the eyes of a dog that can see ghosts.