Both events are listed as in "Iceland / Northwestern Region / Húnaþing vestra", not Westfjords. It's been a couple of years since the event was held, so it's quite possible that the map data for Iceland has been updated to a more correct set, and that the event was originally mislocated to Westfjords.
It's also possible that some portion of land has actually been officially transfered from one region to another. (A cache will always count for the region it's currently in, not what it was in when it was logged, just as the current D/T and all other stats is what counts.)
Looking at Project-GC's current maps, the event location is over 30 km from Westfjords.