Watch the 1080p version.[1] Did they have a control system failure, or was this pilot error? The front fans are steerable, but there's no sign of an attempt to correct the nose-down attitude as the craft dives. Watch the front fan positions. After the crash, the front fans move, but by then the cockpit has been crushed and there's probably nobody in control.

This thing is the same concept as the Skunk Works' P791 prototype - slightly heavier than air, steerable fans - but the flight controls seem to be much less effective and the landing gear is far worse.

[1] https://www.youtube.com/watch?v=DkYbw4R_-RQ