Yeah, you said you wanted him to arrive after Rosa, so he probably JUST got there... or we could delay his official "arrival" if you would prefer. :)
So yeah, the lab people wouldn't know much about him yet, since he is new. It will be a learning process as he settles in and gets to work (and makes first contact with Rosa).
And speaking of Rosa, MEGA PLOTTING ABOUNDS. And her attraction to his power is going to make things easier for him. XD But also something new. He definitely would not be expecting someone to like his power and find benefit from it.