Ewan,
Every flight of a helicopter has risks....risks we all accept and find ways to deal with.
Sometimes it is just plain commonsense, sometimes it comes from experience, sometimes from training, sometimes from education , and sometimes by legal requirement....but we find a way to minimize those risks as best possible.
There is no zero risk flight.....none.
To follow your logic every time a helicopter lands on a roof top helicopter-pad, all traffic on the street below would have to be cleared.....do you expect that to be done for every such evolution....landing and departing?
The video shows an expert, very qualified and respected professional helicopter pilot going about his trade. His reputation, skill, experience, licenses, and very notable accident free record speaks for itself.