Mike.
I'm not normally (ever) one to defend the red arrows. Personally I find their displays an uninspiring waste of their exceptional skill due to lack of imagination in the choreography, but, and it is a big but, one thing they are is safe.
Do you have any idea what they would have had to go through to get a display clearance that allows them to cross the crowd line? The safety case must have been spectacular.
It is not just a case of "we're the reds we can do what we want"
You are much more likely to be hit by a meteorite/lightening than be landed on by the reds.