I don't believe there is anything in a DVD drive mechanism which has enough force to fire out a projectile with enough force to pierce flesh and damage bone as the original article suggests. Even if the drive was spinning as seems unlikely if he was in the process of closing the tray.
The piece of metal is the track which the tray rests on when it comes out of the body of the laptop.
I guess the scenario is this:
He puts DVD in drive. Tries to close the drive tray. It sticks so he give it a real thump with the palm of his hand. Most of the tray goes back into the laptop but because of the force applied jamming the track (or because of previous damage) the track remains out and his palm is impaled on it.
Nothing came shooting out of the laptop, quite the opposite if anything...