vertalop,
You are talking about overspeed. That is fine. We are talking about bursting, a subject that is quite different. A turbine can burst when struck with debris, or from an oil system failure, or from a manufacturing flaw, or when a missile is shoved up the engine's ...exhaust.
The lack of airframe protection against burst is the subject, and a magic engine that doesn't overspeed is a partial answer.
PS You brought it up.