Congrats on the new baby (maybe)
!
I think my girl (her pic is posted) was sired by a lab and she is absolutely fabulous. But I also had exposure to her fam and sort of knew what I was signing up for. The Rott is very dominant with her and that is something you should educate yourself about if you are not familiar with the breed.
That said, you should re-visit, with the most private, one on one environment they can provide you. It is so very hard to gauge a temperament in that situation.
If the animal is still very timid and not friendly or curious I would speak further with the administrators of the facility. Only you and your gut can decide but an animal with fear issues are not for the faint of heart. Please be sure of what you are looking at here...a better description would help...ask the people that work there for more info about his human/animal relations.
He may just be nervous and scared. Understandably.
Ailee