There's a world of difference between "nothing happens with 100% probability" and "nothing happens with 98% probability", even though they can look like the same thing when talking casually.
If you always say "it's 98% nothing", you're still broken because you'll err on the side of "nothing" in all cases where it's something. Your false negative rate would be 100%. For your statements to have any value, you'll have to get at least some of the 2% where it's something right.