There seems to be some discussion as to whether or not OAM is intrinsic to individual photons, or is a characteristic of a light beam which can then be applied to a photon.

http://physics.stackexchange.com/questions/99016/orbital-angular-momentum-of-photon

The question that arises in my mind is: if detection destroys a photon, how can we test any theory relating to its nature prior to detection?

There never was nothing.