I unlocked the bootloader of my Nexus 7 (1st gen/2012) using the Nexus Root Toolkit (on Windows 8.1u1), and then wanted to install CyanogenMod. The CyanogenMod installer (http://get.cm) completed, and I saw the CM robot on my tablet. Then ClockworkModRecovery (CMR) came up and warned "ROM may flash stock recovery on boot. Fix?". I chose fix, and the device rebooted. Then however I saw the standard Nexus boot animation, and it booted into the stock ROM.
I tried repeating the installation, and it seemed to succeed again, but I still only have the stock ROM. I do however now have CMR on my tablet.
What went wrong, and how do I get CM on my tablet? I think I could just copy the ROM to it and install it from CWR, but I like to understand what failed in case someting is wrong.