I don't think any captain with less than one minute of observing what is happening out of sleep could figure out why they are descending 10,000 fpm with the nose up. We normally have competent copilots so don't think this can happen. I always trusted mine. Mine had lots of experience too. These two didn't. We didn't hire people with under 5,000 hrs. It makes a big difference when you hire unqualified people.