On initial observations based on video this seems a possibility. Also other's comments re damage to landing gear would support this.Or he pulled back too high to get to a zero forward speed on the ground and dropped it in but from a bit too high and then tipped over
The surrounding sand seems largely untouched, there appears no wheel track in the sand perhaps suggesting no ground role. May be didn't even tip-over as there is no indication of this in the sand and machine looks very solidly planted? If dropped in hard from too high and then mast has collapsed aft enough to hit prop, while still turning? This picture of prop indicates hit something at speed given cleanly sawn-off?
Based on video, also noted the machine ended up perpendicular to the beach, that is facing the ocean. I did my training near this area and is a very nice 20km+ long beach. Could have been travelling parallel to beach, (may be experienced a technical issue) and had enough time and situational awareness to turn into wind and attempt a near-zero ground speed landing (being best course of action given known surface conditions?). That is, a controlled emergency landing appropriate for conditions?
Is a real shame as nice machine, but best is they survived with only minor injuries.
(apologies for over-analysis, still in COVID lock down and have plenty of spare time)