Pro's dumb thumb it too, from time to time. Problem comes when you do it during a maneuver a meter off the ground, screaming by you at 80kph, a couple meters out from you.
That said, accidents happen. No amount of hard decks, hard distances, rotor rpm limiting, etc. is going to solve it when you're talking about a 1.5m rotor disk spinning at an edge speed of 300+kph with several kilos of mass backing it up. Especially when it comes to advanced and pro pilots that, frankly, 99 times out of 100, aren't going to have this kind of problem and will always push the envelope and safety. It's like any other high risk activity at the pinnacle of performance and skill, it is inherently more dangerous, more risk is taken as one gets better at the activity. There's only so much that you can do, or should do IMO, to make things "safe".
Taking steps to protect spectators at events and whatnot, that's one thing. I understand and agree with that totally. But it would be very easy to go overboard with trying to protect the pilots from themselves and take the thrill out of being the pilot or watching it. We/they know the risks. They are accepted as part of flying one of these machines. That should be good enough.
It's sad this happened, but it is not cause for associations to start bringing the hammer down and imposing various safety measures. 2200 rpm max head speed? 7-10m away at all times, no matter what? To me these smack of arbitrary limits that will do little or nothing to "solve" these instances from occuring.
2200 vs 2400 vs 2600 rpm, frankly, at any speed (within the safe operation limits of the mechanics) if it comes in direct contact with someone it is going to be bad news and quite possibly fatal. These things are swinging nearly meter long *blades* around. 3/4 severed/impaled vs fully severed/impaled is still 100% dead.
Distances away... I'm of the opinion you should fly what you think is safe for your machine, flying type, skill set, etc. I've always been a risk-averse person, though, so I tend to keep distance as best as possible. For beginners and novices, distance during hovering, take off, landing and whatnot is your friend. Yes, no matter your skill, you always need a safety margin, but trying to put an arbitrary number on it isn't practical. And, frankly, such limits are effective only if gravity is what you're depending on to take care of the problem. If you're doing a hurricane and still maintain that distance, if the problem occurs when it is on vector heading toward you, the distance isn't going to matter much. The forward velocity is going to make it a highly dangerous situation no matter what, especially on hard surfaces. Sport flying usually happens at some height, which quickly makes that 7-10m safety margin of far less use since it has farther to fall/glide. My recent 700 crash is a good example of that. Low speed maneuver got out of control. If it happened 7-10m out from me I very well may have been hit by it. As it happened it was very nearly over the top of me when I lost control (started maneuver 5-7m away) and ended up landing 15ish m behind me. Accidents happen and with these machines those distances are traversed very quickly. Safety distances are good for minimizing injury from a catastrophic take off/landing failure (stuff close to the ground) and give some margin for reaction time for lower skilled pilots during low altitude flight, but otherwise I'm not convinced they do much good.
