They achieve that by not generating the scene you see, but a lens warped version of 360 degree view. So you turning the other way doesn't delete what's happenin

They achieve that by not generating the scene you see, but a lens warped version of 360 degree view. So you turning the other way doesn't delete what's happening / generated on your back side. However I expect it to breakdown if you put a blocker in between and remove it. i.e. go behind a wall and come back, or enter and exit a building. Would be nice to play with.