stuck booting into broken Bootcamp (Win 7) volume. any ideas on how to get back to OS X?
I pulled the windows drive and put it in a windows machine to repair it and got it booting over there, but it still wouldn't boot when put back into my Mac Pro.

I was able to get my Mac Pro to boot back into OS X by resetting NVRAM (command-option-P-R after startup sound until you hear it again). Apparently this contains boot disk preference and resetting it along with pulling the windows drive let it 'find' OS X again.

I believe the reason that OS X Recovery and holding option for the Startup Manager don't work for me is due to an aftermarket GTX 760 graphics card. It works great on successful boot, however it doesn't behave the same as the OEM card did in the EFI.