Crucially for O'Neill, neither their goal difference or perilous disciplinary situation were impacted too much - and they remain very much on course for a two-legged tie in November that will determine if they will join Germany in Russian Federation.
O'Neill will be proud of his side's effort in the second half, but will just feel that they could have got on the scoreboard to really trouble the Germans.
"Myself, Lars (Lagerback, Norway coach) and the medical team discussed it and agreed that I should go home to get fit again a quickly as possible", the 25-year-old added.
Sebastian Rudy's rocket after 75 seconds put the classy Germans ahead and they never looked back in this World Cup Group C qualifier.
In Belfast the Dutch referee Danny Makkelie, who was also in charge when Northern Ireland last lost a competitive home game which was four years ago, kept his cards in his pockets which means O'Neill has a full squad to choose from on Sunday.
Five of the starting Northern Irish XI were one booking away from missing Sunday's clash with Norway through suspension but referee Danny Makkelie did not brandish his card once. Equally, it would be nice to go through this campaign and say Germany are the only team that has been able to beat us'.
"There is a real importance to the fact that we make sure of the result in Norway because obviously we want to try and get three points, and we certainly want to make sure we're not beaten".
Sebastian Rudy, whose brilliant second-minute strike from distance set the Germans on their way on Thursday, has warned the other countries hoping to lift the World Cup in Russian Federation that the current holders do not want to hand it over.
"To be seeded wouldn't give us an easier game but we could go into the game on the front foot because we have been recognised as one of the top four teams out of eight in the play-offs".
"Perhaps we could have done better, but the quality of the strike was phenomenal". In the second half, we couldn't have asked for any more.
It was nearly 2-0 a few minutes later when Sandro Wagner got his head to a unsafe cross but a reflex save by Michael McGovern denied the Hoffenheim striker.
"I am satisfied", Low told reporters afterwards in Belfast.
However, as O'Neill himself noted, this squad may be even better than the 2014 World Cup winners. "They'll be a very formidable team to beat in Russian Federation".
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