Stuck in Windows Boot Loader - Cant boot to OSX or Recovery.

I have mid 2013 macbook pro. I just tried to install Windows 10 with bootcamp but got stuck at the boot manager screen because no buttons are working (I tried an external usb mac keyboard with no luck). I powered down and tried to reboot into OS X by holding the option key, but no keys work. I can't reset the NVRAM since the keys do not work. I remember that the boot shortcut keys did not work on this computer before... So, I can't get back to OS X, I can only have the computer start up with Windows boot manager.

I also opened up the computer and removed the internal battery to do a hard SMC reset but this did nothing. I also unplugged ever connector I could find in the computer, hoping that might reset the NVRAM, but no luck. The only buttons that seem to work are the mouse button (which lets me eject the disk) and the power button.

I also tried to boot with a Mac install DVD, but since it is looking for Windows format, it does not accept the boot disc...

It is willing to read the USB ports, I can use an external mouse to eject the discs too, but for some reason won't accept keyboard input.

Any advice to get back into OS X?

Problem clearly explained in Below Video.

https://www.youtube.com/watch?v=7-8LWhbUopM

Any help will be Much Appreciated.