I found a video of a police officer defending himself against a real life knife attack.. it can be viewed at:

http://www.youtube.com/watch?v=3FOUn5qI6Ic

The attack occurs at around 3:12 into the video.
What was interesting for me was the officer's response. which was to irimi and control the head immediately, slamming the attackers head onto the counter.. after this he controlled the knife hand as his fellow officers came to his aid.
Here's a still of the instant of attack: