That pic shows the identical break I had. There's really not much you can do to avoid the potential. My dealer was aware of about 2 in 100 bikes (mine being one) sold prior to the change that broke. Apparently the casing socket that the shaft fits into can break the top part off (see picture above).
Triumph is aware this is a potential weakness which led to a casing change. They also are repairing most that are out of warranty like mine. It it happens to anyone, be sure to force your service dealer to "take it to the top". They may initially say it can't be fixed on warranty. We're lucky that Triumph is basically a small company that still cares about pleasing and taking care of their buyers.