Shouldn't they say more instead of less ? Running 100%load with 42% less failure than running 70% load ?
Doesnt feel right ?

Time to failure is 42% less, meaning that it will fail a lot sooner than if running at 70% load.
42% of what 1 minute or 1 century, or the time it takes for....
If it is 1 century then I would not care as I would most likely be dead, if it is 42% of minute then I would be a bit pissed.