Engine casings are neither designed nor expected to contain complete turbine failure. This is where the whole disk containing dozens of turbine blades breaks free. Doing so is virtually impossible due to the energy involved.
Engine casings are designed to contain turbine blade failures. This is where a single (or occasionally multiple) blade(s) from the turbine breaks free from the turbine disk. The mass of a single blade is only a fraction of that of the whole disk, and so this can (and should) be contained.
This incident looks like the fan blade disk completely detached. Completely uncontainable by any system.
Agree that this complete fan failure is uncontainable, but due to potential catastrophic peripheral damage, it is as I said a very serious incident that they got away with. Part of engine certification is a simulated bird strike and if the damaged turbine(s) aren't contained the test is failed and the engine is not certified.
Yes testing does involve firing frozen birds (chicken/geese) into engines. It also involves explosively detonating a small charge so that a blade (intentionally) becomes detached, and the casing must contain the blade, and the rest of the fan and engine should remain more or less where it is.
However, complete fan disks aren't tested to see what happens when they detach because, quite simply, it shouldn't/mustn't happen because if it does happen it's always uncontainable. If a fan disk becomes detached it shoots forwards at an incredible speed, taking the cowling with it. The fan is providing getting on for one quarter of the thrust required to get an A380 into the air via a shaft, and if that shaft breaks the thrust forces the fan forwards. It then falls to earth still spinning like a demented Flymo. If it hits the ground in a populated area (say Winsor or Slough) it's got a high chance of killing people.
Fan blades break off relatively often. Fan disk failures are thankfully very rare - and smelly stuff will be hitting the air circulation system in Engine Alliance till they work out what went wrong. I expect everyone using that type of engine is doing a quick check of the fan stage today. If others find faults then you could end up with half the worlds A380's (the half not using Rolls Royce engines) grounded.
Another issue is the broken A380. There won't be any existing facilities for fixing it at Goose, and there isn't a hangar big enough to get it in there either. It gets a bit parky there in winter, and the chances of this plane being fixed anytime soon (before Christmas) appear small to me. The Qantas plane was "lucky" in that it landed back at Singapore, which is an A380 and other aircraft maintainance centre, and in a warm (if rainy) location. Goose. Brrrrr.