You have to be careful how you read news articles.This Russian hover-bike made me cringe the first time I saw it fly several years ago. It seems like it is just looking for the opportunity to slice off the operator's legs. It is amazing this crash didn't turn out like a horror show scene. IMO: that guy was lucky to not be injured.
Flying Hoverbike Crashes During Demonstration
From what I can tell, he did not "plummet from 100 feet". Maybe he had trouble controlling the thing., but he certainly wasn't in free fall, and was only a few feet off the ground when he hit.
If I was going to build such a thing, I would have at least 5 blades, not four, and six would be even better. And I would have a computer system do the actual flying with the rider/pilot just telling the computer where he wanted to go.