Since the U.S. Supreme Court has ruled that in certain employment discrimination and retaliation cases the but for causation standard applies, the defense bar has attempted to portray this causation standard has some incredible hurdle for the plaintiff to overcome. It is not.
It is helpful to begin by stating what but for causation is not. But for causation does NOT mean sole cause. For example, a plaintiff does NOT have to prove that discrimination was the sole cause of the adverse employment action - e.g. termination.
But for causation means the straw that broke the camel's back. In other words, there can be multiple other factors that caused the termination. A plaintiff needs to prove that the discriminatory or retaliatory factor made the difference. That the other factors alone would not have resulted in the termination. Here is a good example of but for causation. If poison is given to a man already sicked by multiple diseases, the poison is a but for cause of his death even if those diseases played a part in his death, so long as, without the incremental effect of the poison, he would have lived.
So, at trial, you can tell the jury that the discrimination or the retaliation was the straw that broke the camel's back. Do not fear but for causation. In fact, you can embrace it.