SASless,
The distinction is for the purposes of this thread, where we are discussing when things go wrong, not when we planned the task. For example, when you plan to run out of fuel on a flight, I call that "not an engine failure". I guess I have done that 10 times over the years (on one engine and one fuel cell at a time!)
Think of it as asking a Hollywood stuntman how many car accidents he has been in. He might say "none" since they were all on purpose!