The report concludes that the primary cause of the incident was the use by the crew of the incorrect DME for the approach. The difference between the two DME distances is is approximately 6nm.
Also doing things like this really doesn't help:
"Almost coincident with the FO making the radio call,
the commander asked “what ’s the procedure”, the
supernumerary captain advised the first check altitude,
which was 1,650 ft at 4 DME, before adding “from
four dme we can go to minimum”. The commander
inquired what the minimum was and the FO and
supernumerary captain both advised that it was 740 ft.
The commander repeated
“minimum seven four
zero…..we go for five hundred”,"
