Well he didn't choose to go in the "backcountry"
If you read the article it tells you that he was skiing brockton chair, which for those of you that don't ski seymour is a small chair located on the top, backside of Seymour. He was riding one of the runs on the edge and found pow so he followed it down thinking it would lead him to the bottom of the chair. It didn't and this is when he made the decision to try board from there to the lodge at the very bottom of the mountain. You can't get from Brockton to the Lodge and thats how he got lost.
So he wasn't equipped for the BC because he didn't think he would be boarding in the BC. Yah?