So basically, I was using a spyglass, looking at my brother building a part of the top of his house from my house, and I noticed something strange. I could see blocks being placed and destroyed, but no player doing it. I've also seen this happen in creative with beacon light. You see the beacon block before seeing it's actual light! I don't know if this happens with projectiles, minecarts, and such, but this is REALLY annoying.