I don't understand the rain part. Do they wet the area down to ensure it simulates rain? If not that means the person was dumb enough to go take the test in the rain??? I would fail them just for that decision.
If 15 people fell off, that would be out of how many? 16, 100 , 10,000? Hard to evaluate until you know the total number of those getting a MC rating vs. those who fall.
If you can't avoid an object at 31MPH that you know is there like this test, its only a matter of time before you hit the street hard.
