It is correct that an affair by itself is not MLC. There are a list symptoms in addition to that.....which for most of our MLCers, you can put a check by the majority of them. The "speech" in some form, the urge to abandon or run, hopelessness, seeking happiness/fulfillment....the list goes on.
I also don't necessarily put that much in statistics themselves, but I would also venture to say that the statistics we do know can help us with our Stand. And even throwing the numbers aside......statistical conclusions can be helpful.
For instance, would nearly as many people Stand if we knew that "most" MLCers did NOT make it through their crisis?
Would it be even harder to ignore the OM/OW if we knew "most" affairs turned into long term relationships or marriages?