The accident aircraft seemed to be operating in some quasi-interim flight category, negotiating a phase between IFR and VFR. They certainly weren't on an IFR procedure, no IFR procedure starts at 200'. And they had switched on low altitude mode which is a VFR only mode, so that is a conscious decision that transition from IFR to VFR had occurred. But they weren't VFR otherwise they would have seen the lighthouse 1.3nm directly in-front of them. If VFR somebody has to be looking outside.
Do all the modern tools in these advanced SAR helicopters lull a crew into a false security? I dare say, if they were in a lesser equipped aircraft maybe this accident would have never happened. Or, if this was just a scenario given to them for a check-ride in a simulator, instead of an operational mission, whether they would have done the same thing with the examiner watching them?
I agree with Scattercat. Follow the IFR until you can see where you are going and maintain obstacle clearance by visual reference, no matter how much modern equipment you have that might tempt you to do otherwise. If you are VFR, it shouldn't be of much consequence that a lighthouse isn't in your terrain/obstacle database.