"Illegal" is an observation of circumstances relative to society's laws (which of course can differ by locale). In some cases something which was not illegal later becomes so, when there is enough public pressure to change a law. For my observations, the public nearly never insist that laws become more permissive, particularly for aviation. I accept that in the case of the "Ullswater pilot", local laws were not broken. The justice system did it's job.
"Reckless" is a little more difficult to measure, it depends to some degree upon more activity specific knowledge - which our peers could be expected to have. So when I fly, I consider what my peers might say about decisions I make. I purposefully bring my plane into contact with the water regularly, my peers are fine with that. They would think poorly of me if I did it with the wheels extended. My insurer is also my peer, and would certainly deny a claim I could make following an event where I deliberately contacted the water with my wheels extended.
My peers in marine public service would think poorly of me if I undertook operations on the water without wearing a lifejacket, or immersion suit, conditions considered (I make no remark in this respect about the "Ullswater pilot", as I have no idea what he was wearing, just a general statement). My peers would think poorly of me if I undertook "unusual" marine operations in public view, without telling someone I was going to so as to prevent false emergency call. False emergency calls mean that response to real calls is delayed, and the public bear a cost.
As for the pilot of the Hunter, based upon what the AAIB has said thus far, I believe he flew an aircraft, which was controllable, in a way such that no further application of his control could prevent a crash. It was his job as pilot to maintain a safe margin of control for society's sake, and that margin was not maintained.
Referring to the relevant Canadian regulation, in part:
(2) Except where conducting a take-off, approach or landing or where permitted under section 602.15, no person shall operate an aircraft
(a) over a built-up area or over an open-air assembly of persons unless the aircraft is operated at an altitude from which, in the event of an emergency necessitating an immediate landing, it would be possible to land the aircraft without creating a hazard to persons or property on the surface,
Though I realize that the authority to fly at an airshow may permit lower altitudes, I cannot imagine any authority, or member of the public, who would exempt the requirement to prevent a hazard to persons on the ground. Even if the airshow operator says "Hey, we have an exemption, you can fly low here...", that does not absolve a pilot from continuing to assure they maintain control of the aircraft so as to be able to prevent a hazard to persons on the ground.
If the public thinks that we pilots do not think we are always bound by that simple moral responsibility, the public will certainly insist that lawmakers create laws - more laws, because we pilots took a liberty with public safety...
And Jetblu, you'll believe this: When I once witnessed a microlight pilot seriously buzzing people on a beach - to the point they were ducking, I followed him until he landed, and spoke sharply to him about it. His apparent embarrassment and remorse to me (his peer) was persuasive such that I made no more of it.
When
I once buzzed people on a beach, to draw attention to three apparently drowning swimmers off shore, I reported myself to the regulator shortly afterwords. I was thanked for my effort by Transport Canada (and the swimmers were rescued). I have never needed to perform low level aerobatics
over an assembly of persons.
I respect Jetblu's privilege to disagree with me, but it does not sway my opinion of either event....