Missing Space on Drive using Core Storage after Boot Camp Assistant Failure
The use of Core Storage seems to be a common denominator in problems similar to mine. I used the 

sudo diskutil cs revert [Logical Volume guid]


command in the Terminal application to get rid of Core Storage, and then restarted. Presto! My missing GBs were returned.


  The above command can only be used if the command diskutil cs list shows the Logical Volume to be revertible. See the image included in the posted question for an example.