Always surprised me that people never tried this in the really big events when it matters.
Had a convo on twitter about that, surely if it's more effective then it would be done, so by that logic I'm not sure it's any quicker than just ducking. (Could be completely wrong, but if you need that extra hundredth of a second after training 4 years for a moment surely you'd dive if it was more effective
As said above, I think he was on his way down and would have fallen had he not dived anyway, hence the dive which in this case was more effective.