Ironically, people often dismiss the scale of a problem by saying it was limited to a few "bad apples", when the point of the apple/barrel metaphor is that one bad apple can spoil the whole bunch, so having one bad apple in it is just as bad as every apple being rotten.
Does that one work?
"Ironically" is not the word you should be looking for, there. "Fittingly", or "Unsurprisingly", perhaps. Even if you know not all the apples in the barrel were bad, you know that it was a barrel with more than one bad apple, so you throw that barrel out.