The later A300 and the 310 will not let you fly track/flight path angle with the autopilot engaged. This is the preferred mode for non-precision approaches.You can fly hdg or llz with vertical speed with it engaged but from memory and many sims, ndbs were done using trk/fpa and handflown .Hdg/vs were used for SRA and Loc B/C.The fbw types however can do all of this with the ap engaged.
I looked also at the BHX section of the AIP and found your quote in the noise section.I personally would not have flown an approach as this crew did,but until we here further we can all only speculate.
So they got low and went round-many years ago a BA 747 did a go-around from within a gamepark. What would we be saying about that?