OP, can you give us any more details about exactly how the shotgun broke apart? These pictures give some good info, but they are still pretty limited.
It looks like the problem happened in the bottom barrel of an over under shotgun, and then the right side of the receiver blew out and channeled the force away from the shooter's head and face. Is this what happened?
What interests me is whether the shotgun was engineered to protect a right handed shooter from catastrophic failures, and whether that may have successfully prevented injury. Modern firearms are often designed to protect the shooter in ways that are not obvious. Good engineers don't just make designs that work, they also consider, if there is a failure, how the system will fail.
However, a lot of safety design on long guns is based on protecting right handed shooters. As a left handed shooter, I am always aware of this. I am especially aware that right handed bolt action rifles are designed to protect a right handed shooter in case of failure. And this could be very negative for a left handed shooter. Now I am thinking about the design of this shotgun. It appears pretty symmetrical from side to side, but I am wondering if the design involves more than it first appears.