man this accident is bad...felt sorry for the owner of the car...
this might be not related...but heard a rumor a few years back that the "mat pet" is stealing all the "besi" stuff from guard rails, railway track, manhole cover and even stainless steel gate and sold them at scrap metal shop...talk about time and effort just to get a fix...but a rumor is still a rumor...in one incident they manage to cut the rivet off and pry off the guard rails...but apparently they left it there on the side of the road...maybe its to heavy to carry or lack of means to do so...
so in this case,IMHO, its either bad installation (because i believe rivets are hard to be mess with once install properly), sabotage (the case that the guard rails have been tempered with, which i doubt it since by the look of it,this happened on a highway not some abandoned road where you can bring the tools to pry of the guard rails without someone noticing it) or its just not the driver luck..