the problem is that "Flash_image" is a file that the OS needs to know HOW to flash that recovery to the phone.
that file doesnt exist in the stock rom, so the terminal commands come back with file not found.
I found a link that puts a file on the SD card that contains the needed files, and in terminal emulator your point it to that folder and flash the recovery using a script.
it worked very very well when I rooted a friends OV 2 days ago, but I cant seem to find the link to that right now. when i do, ill update this.
it made flashing the recovery so much easier than hoping the terminal commands will work (which they dont on a stock rom)
edit, here it is.
http://androidforums.com/getitnowmarketing/330813-all-one-recovery-thread.html
basically, follow the instructions, except when it tells you to place your recovery in the folder, replace whatever they have in the instructions, with the recovery you download from the InferiorHumanOrgans github, they have one for new OVs that works great.
rename it to recovery.img, put it in the folder they tell you, follow the rest of the instructions using Terminal in android, and it will flash.