Guro Jerome Teague has very impressive technique, and his knife defense is no exception. He starts by practicing getting offline, which is vital. Knife defense is dicey at best, so you need to build in multiple layers of safety, and the first is getting your torso or abdomen out of the line of attack.
In his first defense he gets both hands on the knife. From the inside,
he goes to a Russian Tie, or a 2-on-1, which is a great position of control. Observe, though that at every step of his defense he is playing, "What if?" What if I miss the parry? What if I miss the rear hand catch? What if the opponent steps out of my throw?
Guro Teague is prepared to go to Plan B at every move. He has multiple redundancies and multiple options. The result is that he can cope with any contingency in a fluid and highly unpredictable scenario.