Ex Cargo Clown:
I'm with BOAC on this, a circle to land is an ILS letdown followed by a visual circuit.
Map shift should have nothing to do with this whatsoever. Unless they have broken the rules and payed the ultimate price for themselves and their pax, ie created a "homemade" FMC based procedure, which would be insane.
But, we don't know whether he flew the ILS correctly to the circling MDA before he departed the electronic guidance. If he did so, then the map would be (should have been) unimportant at that point.
There is always so much for the industry to learn from this type of accident. Sadly, it appears politics (national false pride) will trump safety this time around.