Captjns, very interesting but perhaps you missed the following trom the AAIB report...
at approximately one mile from the runway threshold, the autopilot was momentarily disconnected and re-engaged. The aircraft then went above the glide-slope before developing a high rate of descent.
One mile.... that's 300'
...From the 737 QRH Cat2/3 Operations:
--------------------------------------------------
BELOW 500 RA:-
Autopilot disconnect...............Go Around
Nav Set Failure..........................Go Around
2 or more Deviation Flashes..........Go Around
Stab out of trim..........................Go Around
--------------------------------------------------
The wording of the report.....
the autopilot was momentarily disconnected and re-engaged
....suggests that actions were both pilot initiated rather than uncommanded..... Executing a manual go around from 300' in this circumstance would have been the correct thing to do.