In this interview Diane Warren said she first sent 'I was here' to SYCO (Simon Cowell) for Leona Lewis or maybe Susan Boyle but the response from Simon was 'Its an okay song it just doesnt go all the way for us'.
In a meantime she called Jay Z and Beyonce and they already started recording 'I was here' before Diane even got response from Simon.
from 21:00
So even if Simon and label accepted that song for Leona Beyonce already snatched it.
And the list of 'Leona's' missed songs go on:
We found love
Burn Halo (similar situation to this one) Stronger Impossible Blank Page....I forgot about other ones