I mean is there a chance they were infected later? E.g. they thought source A caused it but in reality Source B ten days later did?
[1] Shennongjia, Hubei. Looks like it's a "county" with about 75k people: https://en.wikipedia.org/wiki/Shennongjia
[2] For instance: he visited Wuhan, self-quarantined immediately after returning which limited his contact with others, then 27 days later developed infection. Every contact he did have was tracked and confirmed negative. That's total speculation, though.