Yeah it was a big slide, but that was Stanley Slide Path and not at the area where the snowboarder is probably lost. Stanley is a huge path that crosses the highway in two spots. Took some cars out four or five years ago and caused me an eight hour drive back to Denver.
By reading the article it sounds like they had a very specific area to search and it couldn't be that huge. A probe line should have found him. So maybe, just maybe this guy went down the Seven mile (3.5 miles long) trail and got trapped by the flats there. It's very hard to get through on a board if the trail hasn't been broken. I hope they thought to send someone down it. It's not threatened by avalanches except maybe once every 100+ years. Definitely not this time. Of course spending another night out there is not a good thing either and that could do it.
I also understand they are not doing avy control on the pass until they either call it or find him. That doesn't help either, as backcountry users who would be out there and might find him are not going to be there. *Edit, they have opened the pass, good hopefully someone will find this guy*