— as the jet approached in a hover, the jettison bay was closed, but shortly before the aircraft began the terminal phase of landing, the jettison bay was then revealed to be open, "unheard of since the 1st flight", he will say)
— smoke billowing from the rear just before the aircraft pitches forward and appears to be a go-around (or malfunction).
anyone who has done a bit of statics and dynamic strength of materials, will understand that the hatch (not the cargo bay) that opens above the fuselage near the cockpit during a landing — towards a point of balance located in the middle of the aircraft - and this to control the descent by the thrust device provided, can be harmful in the event of a go-around, or to constitute in an involuntary and catastrophic way, a kind of fulcrum acting as a lever arm causing a tipping forward, and this is exactly what we see on the video following the ejection of smoke. (in what turns out to be bad timing in the process, but if so, maybe not the only factor)
Here is the video showing the opening of the hold:
Obviously, what I say is not a conclusion, and far from being a complete panel in the tree of causes, (which must include 'pilot error) just observable elements in a trial of their partial recording , but still quite visible.