EGPWS doesn't give much warning on a near vertical Cliff.
As a generic statement it's clearly nonsense, as the 'E' means Enhanced and reflects the fact that there is a look ahead function using a terrain/obstacle database. Normally there should be cautions and alerts from about 30 seconds onwards.
However, the look ahead envelope reduces below 100 kias and is inhibited at 70 kias, which is pretty much the speed they were doing, judging by their groundspeed. Also, if Low Alt mode is used, the envelope further reduces and there is also a Terrain Inhibit function inherent in the MK XXII EGPWS but which is not available in the standard S92 - I can't help wondering if it is available in the SAR machines, as there would be good reason for it.
I don't buy the claims that the waypoint entry was a mistake - it looks like a clear cut cloud break procedure using the westerly-most obstacle as a reference.