They don't want to hear about your problems. They want you to take care of their problems. So Dewberry just works his job, keeps his grief to himself. If employees want to remain reserved, insist that they can handle their work, they should be taken at their word. But the best managers should be watchful of and sensitive to grief's chaotic nature and always keep communication lines open.
Some people are reluctant for fear of rekindling someone's pain.
But they are already in pain. Death, to many, is felt as abandonment. Workers whose grief is not acknowledged can feel doubly abandoned, first by their loved one, then by their colleagues. As for what to say, there is no right thing. Grief is so emotional that no words of wisdom will make things better.