Lights were out with just 10 gone on the clock. If Big John could have stopped the fight at this very moment he would have. So let the record hereby state 10 second first rd KO + 3 seconds of referee lag.
This happens with a lot of fights that get finished. There's when the fighter is out, and there is when the ref steps in. It's pretty well accepted the time the ref steps in is the time the fight is over.
Move along to something useful.