not exactly, untill the clean up step the 6/6 will have 5 damage on it.
if you cast shock and it resolves, the 6/6 will have 7 damage on it and will be destroyed as a statebased effect.
Damage does not lower toughness, so the game will not see a 6/1 at any point, unless you add -0/-1 counters some how.
Careful, I know it wasn't described very thoroughly but I think that he meant that the turn passed, then on his turn he played Shock. In this case the creature would not die because the damage from last turn is no longer on it.
Let me get one thing straight with you. When Condor and an official ruling disagree, 50% of the time the official ruling gets reversed later. The other 50% of the time, the rules get clarified/changed to make the ruling right when it really wasn't before.