Notably, "justification" is an affirmative defense (they don't have to prove you were unjustified - you have to prove you were justified. Guilty until proven innocent, in other words), and in practice must meet a very high bar - e.g. Griggs v. Duke Power Co., that started all this, ruled that an IQ test for management positions is not justified. More recently, a test for teachers where Whites had a higher pass rate than Blacks or Latinos (no word on Asians) was also ruled unjustified:

https://www.wsj.com/articles/black-latino-teachers-collectin...