Apate - unless someone from CHC or Irish CG can answer that question we will have to wait and see.
However, although NVD would help once below the weather, they are of no use during the letdown process other than to spot when you are VMC below.
Even without NVD, the letdown process can still be performed, it is designed to be used in very low visibility day or night - hence the use of radar for clearances. Once established in the hover at the bottom, the AP is used in conjunction with the radar and any visual cues that may be available to close with the target, be that the land or a vessel/structure.
One safety element that would be briefed during the letdown would be the escape route in the even of malfunction - this could be to continue straight ahead and trans up if you aren't pointing at any obstacles or it could be a pre-briefed turn onto a specific heading.
Either way I find it difficult to believe that a crew would trans down pointing at the only obstacle for miles but, if they didn't know it was there (for whatever reasons), that might be what happened.