A quick analysis of the BGA voiding in the Apple 338S120L shows voids as large as 35%. That does not mean this is a problem, but certainly something a quality manager would need to check and validate. Besides, none of the other surface mount components in the iPhone 5S have this level of voiding.

The BGA inspector allows us to visualize the void in a 3D representation of x-y and density as the height of the volume.