Context is very important. It's a little silly to assume some random person would be suddenly attacked by a person who shows a knife, threatens, and then attacks with seemingly no motive. This scenario could happen of course but this context is extremely rare compared to a situation where the attacker is seeking money for drugs or has a beef with the victim, etc. Even then, it's much more likely that a criminal will select a apparent easy victim like a small woman etc. in that case. Most self defense experts I know who have been in multiple knife attacks (note I didn't say knife "fights") recommend moving in as soon as possible. Yes control the knife if you can and use strikes, but continuing to stay at dueling distance is extremely dangerous. That said, everything about getting attacked with a knife is dangerous. I respect Nick for doing these social experiment videos, just happen to differ a little but in some tactics for the larger approach.