If you were Miles Dyson working at Cyberdyne Systems in the universe of Terminator 2, what would you think about the chip you were studying? Personally, I believe I would assume it came from a millitary operation that went wrong - something advanced and secret from the US armed forces blew up in some Afghanistan desert somewhere and someone managed to find the chip to copy.
The robot arm, however, would be much harder to explain, which is a little unexpected given how much less advanced it is. However, it's far more specialised. A chip could be used for anything from missile guidance to robot vision or radio signal encryption. A robot limb in the exact shape of a human arm doesn't involve so much imagination. Either it came from a whole human-shaped robot or it was a prosthetic for an amputee. If it belongs with the highly-advanced chip, however, you have to be talking humanoid robot.
Mokalus of Borg
PS - That "don't ask where it came from" policy just wouldn't work.
PPS - Not with a bunch of engineers.