Smith doesnt blitz - both he and Nonu are slower up than DC: but that's a reflection of Henry's view of the best defensive pattern I assume - given that I have heard him recommend that each man outside trail the man inside - which is different to the league straight line system employed in Aus.
I think they're all facing an attacking pattern they dont recognise.
Nonu seems to realise that there's actually no backline to drift onto because all the poms are in a small area no wider than him: see @ 47 secs in.
I would have thought they would have employed a man-on outside shoulder system for this game to counter the size of Tuilagi and relieve the pressure on DC.
He was there for Nonu to take but he was also there for DC to take.
Only they know.