Has he tried the Single-User mode startup, followed by the command-line disk repair?
Here is how to enter Single User Mode and use fsck to repair the drive:
- Boot the Mac into Single User Mode by holding down Command+S during system boot after you hear the boot chime, you know you will have successfully entered Single User Mode because you will see a bunch of white text on a black background scroll by
- When the Single User boot sequence has finished, you’ll find a small command prompt at the bottom of the screen prefixed by a hash sign (#), when you see that type the following command exactly:
- Once fsck completes, if you see a “File system was modified” message, then you should run “fsck -fy” again until you see a message stating “The volume (name) appears to be OK” – this is standard procedure of using fsck
- Type “reboot” to leave Single User Mode and boot the Mac back into OS X as usual.
Once OS X is booted again, it can be a good idea to confirm all is well by going back to Disk Utility and running the “Verify” tool to check on the drives health.