In his column for the Daily Mail, USA international Hahnemann wrote: "We'll have our weekly 'defence meeting' on Thursday - I'm really looking forward to that, as you can imagine.
He also remarked: "I made a couple of good saves but that's irrelevant.
"I've been replaying the goals in my mind and I'm embarrassed. I never let seven goals in as a five-year-old, let alone in a real game.
"With the first one, I think I could have taken up a different position, and with the second maybe I should have stood up longer.
"And I know the third one was my fault. There was a cross and I shouldn't have come out and Hreidarsson just beat me to it.
"With the fourth, there was a through-ball I shouldn't have come out for.
"With the fifth one, I should have cleaned everyone out at the back post, the sixth one had a huge deflection and, with the seventh, the penalty, I meant to stay in the middle but went left at the last moment as the ball went dead straight."