After the test runs, they beefed up the upper section, probably making the shackle more difficult to attach, plus its designed to separate if top part gets stuck and the cage will decend back to mine.
Got you I think. So the capsule is bulit in two sections and the cage part actually has the cable connection and the top part is just there to deflect any falling rocks. If a rock gets the top part stuck the rider can release the cage and the cable can then let the cage return to the mine.