Pretty remarkable. Would sure like to know the rider's weight and conditions for the break...hammering out of the saddle?...for example. We have all heard of forks breaking right at the headset interface...a stress riser. Location of Spesh relatively long internal expander could be a contributor based upon height of stem on steerer. In this case, the owner ran a fair amount of spacers...possibly worse case.
Check out the Spesh expander below: