BootCamp partition error even though my drive is one partition
I was able to install Windows after doing two things. I'm not positive which one did the trick as I did them both in between an attempt to run bootcamp. These are the things I did in order:


Install reFind... doing this added the missing EFI partition that was mentioned I was missing in the comments for this question.
Use the reFind partition editor to fix the Master Boot Record (MBR) table for my HDD. This partition editor can be found on the reFit menu (launched by choosing the reFit option on the reFind menu)


After this, I launched mac, started boot camp, and the 'status: partitioning disk' message/bar restarted and then it was able to finish partitioning and I have since installed Windows successfully. Any hints on why this finally worked would be much appreciated!

Also, something to note is that after I installed reFind, my partition table (output to diskutil list) was: 

/dev/disk0 (internal, physical):
#:                       TYPE NAME                    SIZE       IDENTIFIER
0:      GUID_partition_scheme                        *500.3 GB   disk0
1:                        EFI EFI                     209.7 MB   disk0s1
2:                  Apple_HFS MAC HDD                 500.1 GB   disk0s2