This is a scary situation. I lost my first beardie this way. Woke up, the light was out. I could have went to work and fixed it when I came home. I would have had someone around that I am sure would have held him while I did it. But that's not me. He was only a couple months old and he was sitting on probably the only spot that the light could have landed on him. But it was up high and I could see him, so I didn't have to worry so much working in the enclosure. It is a front opening and I was leaning in and could have crushed him with my hand. I was trying to set it back in after ultimately replacing the ballast. It landed flush on top of him. Very sad, the kids were devastated.
Happy to report, that the breeder sold me another at a really good price and I make sure he is out of the tank if I am touching anything.