Despite the Waisake Naholo-inspired victory, Tietjens said: "We're pretty down... we've lost two through citings. They played for those guys, we knew it would be tough.''
Of Naholo, who scored three tries in the four-tries-to-one victory over England, Tietjens said: "He played very, very well, the best game I've seen him play for New Zealand.''
New Zealand shut out England early, taking a 19-0 lead at halftime and dominating in all facets, including the penalty count.
They topped their pool after victories over Fiji, Scotland and Australia.
Samoa came from behind to beat Australia 12-10 in their quarter-final, with Canada doing likewise against France to win 17-14. South Africa were 36-0 winners over Argentina.
NZ 24 (Waisake Naholo 3, Tim Mikkelson tries; Gillies Kaka 2 cons) beat England 7 (Tom Powell try; Dan Bibby con)