"But we don't want to use that as an excuse," he quickly added. "We trained well enough, we prepared well enough, we thought, but clearly we didn't get a few things right. They put us under pressure and deserved to win. We're not going to make any excuses about not having the right people."
Hansen claimed he wasn't surprised by Ireland's quick start, nor their tenacity in hanging on to deny the fast-finishing All Blacks.
"They couldn't surprise us - the last time we played them we beat them in the 82nd minute - we'd be very foolish not to think they aren't a very good side," he said. "When you get a good side against another good side you're going to get results like we did tonight.
"In the first half they had all the momentum didn't they. We talked before the game of not giving away avoidable penalties, but because of the pressure we did. They built momentum and then we were chasing them."
Hansen agreed the All Blacks now had much to do on the remainder of their northern tour.
"Ireland certainly put a full stop in it today," said the coach of the end of New Zealand's streak. "We've got to pick ourselves off the floor. It's easy when you're winning. Now we've got a wee operation to do to get up after a loss. While you don't like it, you've got to give all the credit to Ireland and we've got to go away and look at ourselves."
Hansen also has immediate headaches for selections for the upcoming tests against Italy in Rome, return clash against Ireland in Dublin and the game against France in Paris.
He confirmed Ryan Crotty has suffered a serious hamstring injury and centre George Moala had hurt his shoulder. Both are likely to heading home to New Zealand.
"We've got plenty [of injuries]; we've lost both midfielders for the tour, by the look of it, but we'll have a look when we get back in the shed," he said
