He was supposed to be back by 11AM, so they could check out. She reported him missing at 12:30. If a husband goes out for a quick hike at 9AM with plans to be back by 11AM check out time, I think many if not most wives would figure out that something was wrong by 12:30. So I don't find anything unusual about that. He was 90 minutes overdue at 12:30. Even using the 3 hour time frame, he was still overdue at 12:30. Which is why I guess they elected to start an immediate search.
If I had been him, left at 9AM, and knew I had to be back by 11AM, I would drive out, hike until 10AM, then turn around and start back, which would get me back to the hotel by check out time. Maybe he was dependable about things like that, so the wife probably knew that something was wrong at 11AM. By 12:30 her concern would have been confirmed.