If your canary is dead it is time to leave the coalmine.
Human reactions, on the other hand, (putting death aside) have a range of possible motivations and need to be interpreted.
It will be hard to tell what to do from a human's reaction without more detail or a good knowledge of the person.
I work for Exadel, Inc. Exadel is a great company, with great people all around the world. I currently lead the Boulder, CO, USA office.