Julian Nagelsmann launched a withering attack on Freiburg as Bayern Munich's substitution blunder risks costing them points.
A nine-point lead over Borussia Dortmund could be trimmed to six if Bayern's 4-1 win at Freiburg on Saturday is overturned.
That is a live possibility after Freiburg went to the German football association (DFB) with their concerns about the episode, late in the game, that saw Bayern have 12 players on the field for a matter of seconds.
Nagelsmann questioned how Freiburg could justify their complaint, given they were soundly beaten, and said the Champions League hopefuls would have to look at themselves if they get into Europe's top club competition thanks to being handed three points from such a game.
Bayern were 3-1 up when Nagelsmann removed Corentin Tolisso and Kingsley Coman and sent on Marcel Sabitzer and Niklas Sule.
However, Coman did not realise he was being replaced after his number was not raised, and he did not leave the pitch immediately, with referee Christian Dingert resuming the game before the error was noticed.
The DFB will consider the case, and its rules appear to indicate Freiburg may be awarded a 2-0 win.
"In the end I'm not surprised, to be honest," Nagelsmann said. "It is a procedure that lies with the DFB sports court. It has to make a judgement. In my opinion it can only go one way.
"From a personal point of view I don't understand it. Freiburg would not have scored two goals in those 18 seconds.
"I personally wouldn't have done it. I find that you are exploiting the mistakes of a third party to maybe score points yourself.
"I don't know if you can pat yourself on the back with the sponsors at the AGM in November if you play internationally because of the three points you won, which you actually didn't win in sporting terms.
"I wouldn't be so happy if that were the case. I would have clearly communicated to the club that we would not appeal. In the end everyone has to decide for themselves."
Nagelsmann was speaking in Bayern's pre-match news conference for their Champions League quarter-final first leg at Villarreal.
The topic of the Freiburg game is one that Nagelsmann would love to brush aside, given how unwelcome it is as a distraction when there is so much on the line.
Freiburg indicated they had reluctantly pursued an appeal, detailing an "intensive and extremely differentiated process of deliberation" before going ahead.