Partition issue, couldn't unmount disk
I have read several other discussions on this problem, but haven't found a solution.
I recently erased my bootcamp partition of Windows. However, in the middle of erasing the partition, the Bootcamp Assistant froze and my system became unresponsive. I had to restart my computer. When MacOS loaded back up, my Windows partition was gone, but the hard drive space that was allocated to my windows partition is now "Free Space"
When I reboot into Recovery Mode, I try to extend my Macintosh HD partition to my full hard drive capacity. However, the attempt fails by saying that Disk Utility couldn't unmount the disk. Is there a solution to this that doesn't involve a clean wipe and reinstall from a Time Capsule Backup (for sake of not taking a long time to restore from backup)?
MacBook Pro, OS X Mavericks (10.9.2)