*shrug* I dunno.
I'm (thankfully) not the one that got gouged.
But yeah, it is feasible that an edge could do it, a different binding type could do it, or even a ski pole...
But according to that unfortunate soul (he comments later in that topic):
'the heelpiece of the binding got me. well thats wat the doctor reckons, cuz he was picking a few pieces of blue plastic out. all u kids watch out for look pivot bindings - they'll get you.'
Way, way sketchy IMHO
But hey I guess that's just a risk of the sport!