They had nothing of the sort.
If they were in the area that was approved for the sightseeing, and not below 6,000ft, and had been identified on radar, what would whiteout have to do with anything? there is no high ground in that area, and if they had of been identified on the radar do you not think the radar operator would advised them if they were approaching any high ground?
As has been stated before, if you want to break the rules you have to be 100% certain you are right.