Dude, I flashed this manually using "fastboot flash recovery recovery.img" and it kept flashing the screen after choosing reboot recovery. I verified to make sure the MD5 matched
@agrabren's MD5, and it did match. So I flashed it again, it kept flashing. The flashes would happen quickly and it would go super dark, then gray. Super dark, then gray. So on and son on. I was about to try the other custom recovery.
I decided to use your toolkit and it installed CMW recovery. I chose "reboot recovery" in bootloader, thinking the screen would just keep flashing until I held the Shield button for 10 seconds and forced it to turn off. It went to CWM recovery! I don't know what was happening different, but your toolkit flashed custom recovery just fine. I'm sick and without my editing machine right now (it died and I'm waiting on it to get fixed), but a video will come. I have MANY Shield videos planned, I just need my computer back.
But after using the toolkit, SUCCESS!
http://instagram.com/p/e-KWUcj1Vs/