The Machine didn't send her a number, just an address. Because why? Does this guy not have a number? Is he the threat? Shaw considers him with a scrutinizing gaze. She's not giving away anything, not even an 'I don't know,' which is the unhelpful truth, but still a piece of information. She's been in this business long enough to know that you neither confirm nor deny. Not until you have some information of your own.

She should ask questions first, and then shoot, if necessary. A 'scalpel.'

"What's your business with him?" she asks at length.