Such projects come up with a certain frequency, nothing "very unusual" about this one. For myself I have nothing but admiration for these people, and the amount of dedication and budget they put into their projects.
The comment about not availing of plans and other documentation available on the www seems very one-sided - the www is not as omnipresent as some believe.
Neither can the effort be totally uneducated - at least the need for reduction gear was seen, and catered for.
Looking on from a distance, one can easily say the combination of 500 kg weight and 5,5 m wingspan and very limited power was asking for trouble. But that's too easy a criticism. And perhaps it wasn't even totally impossible, with a thick enough wing.
The one thing I would say he ought to reconsider is climbing to 50 metres at a first try. The first try should be a take-off and immediate landing, never higher than the landing gear can absorb falling from. Then again, those 50 metres were probably only wishful thinking.