Heading east? How?

I just saw a documentry here about the 3rd plane that crashed into the ground, and in it they say how the stewardess rang her husband, and she didn't know where they were heading so he asked where the sun was and she said it was outside the window or something and he said "you must be heading east".
How did he know which side of the window she was talking about though? Surely it would depend on if the sun was out the left or the right to know wheter she was going east or west, right?

Well if she saw the sun right out the window wouldn't they have to going north south or visa versa?

If they were heading east in the morning the sun would be infront of them, no?

Well he asked where she was, she said she didn't know, so he asked what's out the window and she said "water" and so he asked where the sun was, she said "infront of me" (I think).

Meaning they were heading east...