He's barking. His initial reaction is probably as disproportionate as it could get. The thing's hurtling towards him, like, RIGHT towards him, and his first thought is to just breathe in a bit?
I guess as an enthusiast I should commend his immediate resumption of photography, but I think I might have to spend longer dusting myself off (and checking what happened to the folks inside the car from which a whole side was removed) before going for the shutter-release...
That really is complete madness!
Rob.