I suppose the short answer is that they aren't shining the laser at aircraft.
I imagine that such a show has to assess and address any dangers or hazards involved in the show. Those lasers don't look like toys and a flash in the wrong place could be very dangerous. Fortunately I suspect they are operated by professionals and not a few dropkicks looking for quick thrills.
For the sake of our Qld colleges I just hope the show is on at full moon.