How did he get the disease? Sharing fluids with a sick person? Something about this doesn't make sense. If you can't get this from someone who isn't showing symptoms, there must be a lot of people sharing body fluids with Ebola patients in Africa.
I think you are exactly right. Often the infection comes from caring for a sick family member. He apparently started showing symptoms 4 days after arriving from Africa (Liberia I think). Four days later he was diagnosed. That means that people who were in contact with him after he was sick but before he was quarantined will need to be isolated and tested.
In Africa many people don't trust hospitals or doctors and prefer to go to traditional healers. They have nothing to offer people and when they go home, they get sicker and infect more people. In the west I doubt this would happen. if anything we put too much faith in medicine and what it can do.
Just to point out how culturally different it is in Africa, I heard a radio song to help prevent the spread of Ebola. Since new cases are transmitted from eating bush meat, the refrain goes: "Ebola; If you find a dead monkey don't eat it, Ebola."
Now if you have to tell people not to eat a dead monkey they find... You have a real disease problem.