Riddle

You're in a room with 4 others. The discussion is about work on a factory floor.

Their Boss is interesting. He has a rare genetic condition that enables him to absorb huge amounts of toxins without any side effects. But this would make him a danger to the workers if they were to come into contact with him. So, he usually controls things from a distance.  

One of the guys explains the pain he felt before the third one came to the factory and made doing the work easier:
"I was trying and trying to do my job, but it was so hard! I kept failing. There was so much that needed to be done. I could tell I was being monitored closely, because a voice would come over  the loud speakers saying,
'Khm khm, are you sure you want to lift that one?'
I'd ignore it thinking to myself, 'It's ok, I've got this.' Then I'd stuff up my back and be out of action for a few hours, or I would take a wrong step trying to carry a heavy item and twist an ankle. I would hide behind some boxes and cry sometimes, because I felt so incompetent and was so ashamed."

"It was the same with me," the second guy says. "Occasionally, I was in such a bad way a voice would come over the speakers and coax me into the camera's field, into the light so the Boss could take a look. And there were some times I'd hear
'Ouch! That must hurt. It's going to need serious attention!'
After which, the Boss would come down to the factory floor in what looked like a space suit and give me medical treatment.
He would say,
'I am training a Supervisor who will help you with this. Just keep doing what you're doing as best you can until that time.'

Once or twice, he more than dropped a hint about when the Supervisor would be sent.  And sure enough, on the very day I was expecting it, this guy rocks up. But he really didn't look like a Supervisor. In fact, at first I thought he was just a young apprentice."

At this, the third guy chuckles, "I tried to tell you."
"Well, you certainly don't look your age," the second guy chides back, "I thought you were pulling my leg."

Then he goes on, "We were trying to maneuver a long item and accidently knocked it and chipped the corners. Boss was looking at it form a birds-eye-view; kept trying to direct us over the mic from the control tower.

But it was no use. We'd get our left mixed up from our right. We'd come in at the wrong angle and have to back up and start again. Then this 'Newby' arrives." The three laugh. The fourth guy is still really quiet. Like kind of awkwardly quiet.

Then the third guy (Supervisor) says, "I remember that day so well. I can't blame you for struggling, that panel was so long and kind of out of shape. Remember that other one with the really sharp edges? That hurt!" The first two guys say in unison, "Sorry, we didn't think it would slice you up like that!" looking ashamed.
"That's ok, I can handle it," he says.
Then the first guy looks at you and says, "there was blood everywhere, it was horrific!" You try not to imagine it.

Sometime later, you are still reflecting back to the conversation between Mo, Dave and Josh, and trying to remember some of the other things they said about the Boss and the job. The fourth guy brushes past and you recognise something familiar about him.
"Hey, are you the guy that was there when I got introduced to the Supervisor?"
"Yes", he says in a very unnatural voice. "I was there. But Josh isn't the Supervisor. There are no supervisors here."
"Come again?"
With deadpan face and strange melody in his talk, he replies, "Just do your job. It's very simple."
You are kind of offended, but confusion and curiosity get the better of you.
"But you heard their story!"
"Yes, I did."
"...about the day Josh cut his hands while helping the others. You know...blood everywhere!"
"No," he says. "You misheard. It did not happen like that."
"What do you mean?"
"We workers don't bleed."
"Well, I do."
"Yes," he says statically. "You are a loser. But we are the workers here. You're just a cleaner."
"Oh?" ..."but they said they were struggling and in pain before Josh came."
"No. They would never have said that. We workers don't feel pain. And we don't make mistakes."
"Were you even listening?"
"Are you questioning me?" he states. "I just told you. We workers never make mistakes."
 
You start to think perhaps you're going crazy. Then you recall the end of the original conversation. It went like this:

Dave "We were really upset when you had to go back to work in the control tower."
Josh "Yes, but that's why I gave you the HSP radios--so I could guide you when you're stuck."
Mo "Yes, you did. It's just like the loudspeaker system, only better. It's more personal and you are able to explain things to us in a way we understand because you've worked on the ground with us and can really see it from our perspective."

So you turn to this guy again and say, "Do you have an HSP radio?"
"A what?"
"HS Paracletos radio... you know, the one Josh gave to workers before he went to the control tower."
"Oh, Paracletos! Yeah, that would be me. I know everything that you will ever need to know about the workings of this place."

.../.../.../.../.../...

Now for the riddle:

Which of the 4 was a cyborg?