This entire trip should be a case study in what not to do. A college professor no less and had taken a survival course? North Rim access closed due to snow in winter is common knowledge. 10 minutes of trip planning on internet would have solved the issue of even thinking they could get to north rim. She is alive only due to fitness but hiked in wrong direction to get help. Husband goes to nearby high ground and gets phone coverage. This was disaster in the making and only dumb luck pulled them through. Use brain before opening. Past performance is no guarantee of future returns.

SPOT locator, at least a general map of the area, use of compass are all essential in addition to the other survival items. In this case they did not need to walk anywhere. Just stay with car. Oh, there was also a predicted and pending winter weather storm.