Niko Kovac said he has never seen anything like Bayern Munich's 5-4 DFB-Pokal quarter-final defeat of Heidenheim but was unhappy with his side's lack of concentration.
Niklas Sule's red card after Leon Goretzka's early header opened the door for the second-tier side, who led at the break thanks to goals from Robert Glatzel and Marc Schnatterer.
Substitute Robert Lewandowski, who was deemed too ill to start, came off the bench at the break and set up Thomas Muller before putting Bayern in front, with Serge Gnabry extending the lead.
But Heidenheim hit back against the 10 men once more, with Glatzel striking twice in three minutes to claim the match ball before Lewandowski's late penalty settled a breathless encounter.
And although Kovac conceded the first red card of Sule's career put his side in an uncomfortable position, he was frustrated by the errors made by Bayern.
"The red card changed our calculations, so we had to react and change to 4-4-1 to get some compactness," he said after Bayern booked a DFB-Pokal semi-final spot for the 10th year in a row.
"With the change in the second half, we got into the game better, then turned it. What annoys me absolutely is that you cannot manage leading 4-2 and then we get into trouble.
"It was wild, an open game, which I do not like in shape. Finally, we have a bit of luck, which you need in the cup. I have never experienced such a game."
Heidenheim's coach Frank Schmidt was less surprised the match was such a thriller but felt Bayern's ability to bring on Lewandowski and Kingsley Coman at half-time proved decisive.
"We imagined it would be such a wild game. That we manage to keep the game open through passion and scary work in the defence," he said. "Too bad that it was then relatively easy for us to fall behind. The game is different with the red card.
"Nevertheless, it is not obvious that you turn the game at half-time. But we did that with two brilliant offensive actions. In the second half Niko changed again, we could not defend this quality. Nevertheless, we kept our shape in play at all times.
"We have such a mentality that we really only stop playing the game when it's finished. I'm so sad that we exited. I think, it could have been the other way around in such a wild game.
"Today we have been able to give a business card, which shows Heidenheim. It was fun, it was an awesome evening from our point of view with the wrong result."