Eight has to give this a long think. Considering they were on the train, it wasn't as though the man could run off with it. The worst that he could do would be to damage it, but if it the part wasn't working anyway...?

As she handed over the part, her second hand came and gripped the one that had been extended to her. "May I have your name?"

There was no insurance, of course, that having his name would ensure that he would be more considerate of what she was doing. But before she released the part from her care, she wanted to know at least that much.