Vehicle subsystems are (or should be) routinely overstress tested to determine durability and failure modes. 100% of a published spec. is never (or should never be) anywhere near the limit of catastrophic failure.
Sounds like it was an inadequately designed test that should have been run in an intrisically safe area. Either that, or one of the operators pooh poohed the regs and brought a prohibited device into the hazardous area. Just a guess.
Even as a paint room foreman a certain percentage of my quality control tests were destructive tests that were well beyond what the painted surface would ever see under normal usage.