OK, I think I see the "discrepancy". You did not state what OS you are using, but if it's Sierra (OS 10.12, 10.12.1, 10.12.2, or 10.12.3), the instructions are "somewhat" different.
I am using the latest version of Sierra, OS 10.12.3, and I just booted my machine to that (hidden) Recovery HD partition. Here are the instructions:
- Turn off your Mac (choose Apple > Shut Down).
- Press the power button while holding down Command-R. The Mac will boot into Recovery mode. ...
- Here is the different part. At the top of the screen, you'll see the menu headings:
macos Utilities File Edit Utilities Window
4. Click on the Utilities heading (the one between Edit and Window), and select Terminal.
5. Enter resetpassword (all one word, lowercase letters) and press Return.
Hopefully, that will work. I actually have never booted to that (hidden) Recovery partition, as I have other ways of recovering. But, this is good to know. (In actuality, there are 2 more options under that Utilities menu: Firmware Password Utility, and Network Utility. I wonder what they would be used for).