Blockexplorer says 20 seconds, I don't think this will be a problem.
yeah, that's the time that each miner stamped their block with, but in reality they poppped up on bitcoin monitor in much closer proximity.
anyway, good to know that the 2nd one of these is valid and was built on that first one.
imagine if it was the same person who found 2 blocks one after the other... what a bonus.