The NA14 photoproduction experiment, carried out at the CERN SPS, has measured the inclusive cross section of events with a prompt photon at high pT in the final state. Here we present a study of the topology of the final state of these events. The topology differs from that observed for events with an identified π0 in the same kinematical domain. Using these differences we have extracted the contribution from the Born term to the inclusive prompt photon cross section. The result is in good agreement with theoretical predictions and supports the assignment of a fractional electric charge to the quarks.