Help with this problem please too hard:

Three positive integers are written on a whiteboard. David calculated the highest common factor of the two of them and obtained 1 000 004. Rose and Stephen did the same obtaining the results 1 000 006 and 1 000 008 respectively. Emily is sure at least one of her friends made a mistake despite the fact that they calculated the highest common factors of different numbers. Is she right?

Thanks heaps in advance.