I noticed it in declassified, but not in the episode. So I don't think it matters, they could have at least refilmed it though. There again, there have been plenty in doctor who aswel, just who-fans don't like to point them out lol. He can hardly be blamed after all those special effect things do actually hurt and it would be a natural reaction to move. Also his hands weren't actually tied which didn't help things, perhaps the budget didn't stretch to ropes lol.