The NCL Pearl is a state-of-the-art cruise ship, with lots of high tech security. I am quite sure that after the details are sorted out, NCL will have video survillence of exactly what happened and the exact time of the incident. They have security cameras everywhere, in the hallways, outside decks, and views from the sides of the ship. They also have top notch security personel.
Most of all....let's hope they find the lady, and that she is safe. It's difficult to speculate what hapenned abroad this ship, and what went on.
As with any investigation, time will ultimately tell what happened.
This is not an isolated case, many cruise passengers have went overboard in the past 3 years. Some have actually survived. Let's hope this may be the case.