JLP's points were all good. i just had to come up with an understandable explanation of why radius of curvature is important, and if that is a factor that is where you may get failure. I have seen enough pitons and such bent all out of shape without breaking to cause me to worry about things in addition to bending.
The picture I saw showed a bolt broken cleanly with relatively little bending. That and Doc's discussion of how this material is alloyed convinces me absolutely and never to count on such a bolt as my only protection. But that is me and you folks are you.
I only looked at the bend. The first thing to mind was heat
being the weld applied to the element. Usually a proper weld is
stronger than the original state of the element. However the
heat dissipation upon the surrounding area may cause weakness
below the original state of the element.
KRail barrier protects persons, places and things behind the
barrier from oncoming traffic. Persons places or things are not
protected from oncoming traffic when in front of the barrier.
Again with this said the bolt appears to have possibly been
placed incorrectly and or the bolt was being used as a anchor
for a guideline and placed under load of varying angles due to,
perhaps wind (continuous shock load) in which case perhaps a
different element maybe a better choice?