Thread drift, but a little, I suppose....

I wanted him to have docking practice, and I wanted to get out on the water, so he could fly his required five solo water circuits for the seaplane endorsement.

Good thing. Unlike floatplanes, flying boats are landed on the step, much like a wheel landing, so it is entirely possible, and desirable, to touch the keel and then allow the plane to slow, and settle into displacement at about that pitch. Stall landings work too, but are much less graceful. OTOH, landing a floatplane on the step is courting disaster.

Truthfully, I don't really know, but I'm guessing it was about what is depicted in the video, though water conditions were just a light ripple, so it wasn't waves causing porpoising. My mind chooses to not recall a rather violent ride, and I'm just fine with that, so I cannot describe the rest of the coming to a stop. Flying boats are wonderful on the water, much more maneuverable, and mishandling tolerant than floatplanes, but do require a precise touch, and are prone to porpoising if it is allowed to continue.

To the topic at hand, I had a super student, with great attitude, an attentive desire to learn well, and decent experience on type - and between us, we still got it wrong. I have also started to train a Lake owner with zero time on type, really poor flying skills, and a less than ideal airplane (no shoulder harnesses at all installed). After some runway training, then more, and more, and more, totaling 60 circuits over two days of training, I never reached the point where I would ever send him solo (in any plane) on wheels, much less on the water. I never landed him in the water, and told him that I would require more basic training on wheels for him, before I would return to train him. My challenge was that he had paid my expenses to fly literally across Canada to train him, and now I would not - and I did not. Someone else did, as I have heard tell of scary GoPro videos, attributed to him. Nice fellow, but inadequate hands and feet skills, and precise flying skills to enter into water training with me. I could not convince him of this, as his flying school (I met some of them) kept telling him how great a pilot he was.

Student attitude makes a huge difference in train outcomes, and behaviour post PPL. Human factors tries to open this topic, but its the instructors, school operators, and onlookers (like PPR Aerodrome Masters) who have a role in identifying poor attitude pilots, and perhaps mentoring - But, I agree, a few people just won't listen....

This chap made it through the trees (just) on a performance-restricted departure. It's a scary watch. There are some parallels with the Troutbeck incident.

However, the driver was far from "low-hours", and the appropriate perf. calcs. were done.

A key comment:- "just because an aircraft can (theoretically) do it, does not mean (near it's limits) it will do it"

This was a highly successful middle aged business man. He was clearly not without intelligence.
His IQ was likely to be high average or even above the average by a significant amount.

There are certain aspects of this accident which I would suggest are more than just careless conduct.
I have chosen just four to illustrate my thoughts.

On 8 August [after the LST on 30 July but before licence issue on 27 August] he flew into a 330m strip with significant obstacles. A club FI was so concerned that he drove to the strip and told him not to depart. His advice was disregarded. [page 8]

Frequent mention was made of not using the shoulder straps [pages 8/18/25/27]. It appears that they were not worn on the fateful day at Troutbeck, with the report suggesting that had they been worn the impact might have been survivable.

On the accident day, the MTOM was exceeded on two occasions before arriving at Troutbeck [page 10].

Cocaine had been consumed a day or so before the accident according to the toxicology report but was not a factor in the accident day. No mention is made when the medical certificate was issued. No mention is made when the deceased first started using cocaine. The “effects of cocaine” are well documented on the internet. Such activity is incompatible with medical certification.
Various quotes from the FIs might indicate somewhat erratic behaviour [page 8]. Was this his natural personality, or where other factors at play? They had certainty and forcefully attempted to educate him. I am sure that they tried their best.
As someone who started to instruct as an AFI in 1984, I recognise the challenges they faced.

In English criminal law and in the law of tort recklessness may be defined as
‘the state of mind where a person deliberately and unjustifiably pursues a course of action while consciously disregarding any risks flowing from such actions’.

There is likely to be a broad range of opinion which I entirely respect. We might have to agree to disagree as they say.

I was referring to the behaviours and disregard for advice, as well as aircraft limitations!

Humans are pack animals. The instructors were likely seen as not his group. What the AAIB cannot investigate is his flying social group, where this sort of flying was discussed.
A C150 Aerobat joining with 2 Maules on farmstriping is a labrador running off to join the wolf pack.
The reluctance to wear shoulder harness is weird. Otherwise he was just moving into a new flying scenario, which was possibly unfamiliar to the instructors he knew.

Weird but not that unusual. I was flying with a North Sea offshore pilot one day and noticed that his shoulder straps were not fastened (the straps were behind his back). Assuming he had inadvertently forgotten to fasten them, I pointed it out, and he told me that he didn’t like wearing them (found them uncomfortable). I let it go for that flight (he was the Captain), but on subsequent flights when he tried to repeat it, I insisted that he fastened them.
On another occasion, a different pilot, with him driving a company hire car on duty (on the way from simulator), he fastened the seat belt over his empty seat (to stop the warning sounding), and then sat on top of the fastened belt. Again, asked him why, he just said he didn’t like wearing seat belts.

yes - there were a few dinosaurs back then!

Sad to say, the first incident was UK summer 2019, the other one was around 2017. First one reached mandatory retirement not so long ago, the other is still flying but close to retirement.

Oh! I assumed late 80s/early 90s - I didn't know you'd gone back later! That's amazing then.

The Coroner ruled that is was a ‘tragic accident’ at an Inquest shortly before Christmas.