It appears to me, on the basis of the news report, that when the SOS was reported, a check was made of both the locals and the guests at the resort. Every one was accounted for.

The missing couple had checked out and were therefor presumed to have left the area. It's probably not practical under normal circumstances for the RCMP to trace and contact every one who has been through the resort during that time frame. Given that everyone appeared to have been accounted for.

I am of the view that had the RCMP had reason to think that someone was in trouble, they would have made a search.