But the problem of late discovery are the ones that are (far?) bigger than this ones, the ones that manage to reach the ground in sizes much bigger than a pebble. Are we detecting all the dangerous ones (and little less dangerous but big enough), and with enough anticipation? Had been in recent times surprises of big enough asteroids passing close enough?
I suppose that in the end, we are playing with odds. It didn't happened for long enough, most that get close is harmless, and I suppose that if there are some harder to be detected (i.e. darker/low reflective ones?) they should not be the majority. But from time to time we have events that reminds us the bet we are playing.
Well, at least not in one piece. Pieces of the previous one over France (which happened to be detected by the same person before it entered the atmosphere), have been found: https://karmaka.de/?p=32369