Well, think about it a minute... if your tipping bucket tips at .01, you'll always be .0099 Lower than what you might compare it to.
You're not plaing with a 'full spoon'. And if it stops raining, and evaporates, you've lost .0099 " of Precip. This could allow a layer of volcanic ash or meteorite dust to accrete in the spoon, it'll tip "faster"
If a bird parks his butt on the CCR gauge, you'll miss what runs off his tail...
If you've had an itzy bitsy critter lay some silk on the tipping pivot, it'll 'reset' slower, and be "less than"...
Yeah, miniscule... silly. But you're working apples and oranges here, Man with two watches never know what time it really is.