iPhone 5s Phantom Photos Will Not Delete
I had the same problem.  iOS devices have a delayed delete function.  To solve the "phantom photo/video" issue, do the following:


Delete what you want deleted
Open Photos app on iOS device.
Open 'Recently Deleted' folder. 
Delete items from phone permanently.
(Re)plug phone into laptop and Sync.


The photos/videos size drop to appropriately after I did this.

Cheers.