Nick's post indicates that the problem won't happen again since the shaft and gear were redesigned - therefore not much point in teaching it in the sim
Sometimes the dog of fate lifts its leg and urinates on the pillar of science. Never believe in the word never, as in, it can't happen. The only MGB problem in this regard I ever had was the rotor brake quill on a 212 snapping in half for some unknown to me reason. Bevel gear dropped and bounced around in the MGB and the brake disc left lying on the cabin roof. Any part can fail for any number of reasons, heat treating, tooling marks, corrosion, inclusions being a few. I'm sure some one once said a MGB can't fail and release the main rotor. We know better now, and still await the initiating cause.