I saw a lot of "using the engine" to slow the car instead of using the brakes, and that puts very large tensile stresses on the rods and bolts. Long term deformation of the big ends and bolts will trigger a failure and its exacerbated by the heavy OEM rods.
While using better rods (Pauter, Carrillo, Arrow, Pankl: 4340 or Titanium, etc) will certainly make a big difference in durability, none of these are totally bulletproof when the engine is operated in such a fashion,...
JMHO, we don't recommend using stock rods when expected peak RPM's will be over 7300 due to excessive bearing loads.
I'd be curious about how many hours on the engine before this happened.