Then it's irrelevant. The point is that the remainders are evenly distributed as the integer is incremented, with at most a single round being short. That's just how the math works.
"A single round being short" is exactly what they're talking about.
Edit to add: whether that's a big enough effect for the use case they're talking about, I don't know. This sort of thing is definitely significant in cryptographic code, though.
