Thing about this is where do you draw a line? For instance this weekend will see a display at the MotoGP at Silverstone and there are displays at all kinds of sporting events with roads and spectators and sometimes no real obvious crowd line. What about events like the RedBull Air race?
The point is this shouldn't be about trying to achieve no flying over roads because there will always be some sequence of events that ends badly [take the Citation biz jet that ended in a housing estate having had a problem climbing out from Biggin Hill a decade ago as example]. Some have suggested do everything over the sea, except that hasn't thought about the very poor horizon that gives.
Time will tell the causes of the most recent events however given some of the people caught up in this have no or little interest in things aviation those with an interest in these things would be done a great service if (for example) elements of recommendation in this AAIB report were made clear at the earliest opportunity - which they could quite easily do. That way we would be showing the world the level of professionalism that is involved in these events.
https://assets.digital.cabinet-offic...009_G-HURR.pdf