Absolutely not a common thing at all. I would have your father get in touch with magnum research or whomever is making the DE now. Call the customer service department and tell them what happened. Talk to the store he bought it from, maybe they can help you. The DE is a very robust and rugged gun. Obviously there was a metallurgy problem or manufacturing issue with the ammo.
Did he inspect to see whether the barrel is clear of any obstruction/s before he pressed the trigger? You see, we sort of have an incident like that wherein the barrel ended up similar to an opened petals of a flower. What went wrong was that young sonny boy was trying to site the gun. He forgot to remove the bore site laser from the barrel.