As one who knows about such things, I wasn't at all surprised that there was soliflucation around the sides of the dam - there were no discernable abutments to anchor the dam wall to the sides of the incision. Presumably these were not deemed necessary because of the err, short operational life of the model dam.
Excellent flying in that DC4 (?) - distance shots reminded me of the CP107 Argus (based on the Britannia). I remember seeing one as a cadet in the eraly 1970s.