"after the landing gear unexpectedly fell off the plane"
Well, I'm not too sure it's not far off what happened
Looking at that video, it seems to me the nose attitude falls in the last few seconds (~0:19?) - about as the aircraft transitions from grass onto hard (taxiway?). Nobody seems to be allowing for the fact that the "off road" and back "on road" excursion may have caused the NLG to fail?
Why the excursion started who knows, but KLM had a similar "off roader" at BCN after a bird took out the NWS cable(s).