Compare the letter in which Sheila had sent from Japan,to those which are being investigated at present.
There's a marked difference in the layout of the one to Colin,even though it goes off on a tangent where she states that those around her were " scared of her because of the staring " and she wanted to go home because of " odd " feelings that she had.
Anyone who can fly that distance can't have much wrong with them ! Competition too much ?