In a perfect world judges would be able to overrule a ref for me, as clear knockdowns sometimes are missed just as slips or pushes are sometimes called knockdowns. I agree that it shouldn't be encouraged and would get way out of hand, after all the Ref is the guy in the ring and as long as he's doing his job there is nobody in a better position to make those calls.

You can't have a 9-9 round by way of the 10 point must system as far as I know. It's a tough call if you have a guy dominate a round and then go down on a balance shot without getting hurt, say. Is that 10-9 or 10-10? I imagine this happens about as often as a 10-8 round is awarded without a knockdown occurring, which is also well within the rules but rare to see scored.