Look at CAP 403 if you need to know details regarding overflight of spectators, it says...
Pilots should plan their flying sequence such that they can always regain the display line without infringing the minimum lateral separation distance from the crowd line. Effects of any on-crowd velocity vectors and on-crowd wind component must be taken into account.
So pilots can fly towards the crowd (and over it in some cases if they have specific written permission from the CAA GA Unit).