Despite the loss, and his frustration, O’Neill still had time for a joke with a member of the German media.
“Having looked at the stats, ironically Germany played more long balls than us in the game,” he said.
For his part, Julian Nagelsmann, whose comments after the reverse fixture in Cologne prompted O’Neill’s quip, was relieved to get through a “tough” game.
“The second half was all about defending,” Nagelsmann told BBC Sport.
“As I said before the game it was a really tough opponent, a lot of long balls and they fight and we had to fight as well.
“It was a good step in the right direction to beat a team like Northern Ireland and to fight for second balls and be as tough as the opponent.”
Top spot in Group A is now a long shot given Germany have put their grasp on automatic qualification.
But second place and a guaranteed play-off is still on the cards ahead of November’s two qualifiers in Slovakia and home to bottom side Luxembourg.
It may not be much consolation now, but a play-off as one of four Nations League group winners seems to be a more secure fall back given other results across Europe, if Northern Ireland were to miss out on the top two.
So, after battling but falling short against one of Europe’s giants, this young Northern Ireland side may be down, but they are definitely not out.