It's not impossible to discipline employees who complain of discrimination. They're not untouchable. Just make sure you can show that the discipline flows from objective performance factors, not retaliation.
Still, in such risky situations, ensure that higher-ups scrutinize the reasons for the discipline. Always undertake an independent review; don't take the decision maker's word at face value.
Finally, make sure the independent review is substantive and meaningful. Courts will look down on reviews that simply look like a rubber stamp. So if you don't possess the specialized knowledge or technical background to understand the reasons for the disciplinary measures, arrange for someone with that knowledge to conduct the review.
Recent case: Godofredo Hernandez, a 10-year technician, complained to HR on behalf of a co-worker who said she was sexually harassed by Hernandez's supervisor. HR investigated and found no harassment.
A month later, the company terminated Hernandez for making various technical mistakes. The proof? Hernandez's supervisor prepared a list of Hernandez's mistakes. An HR director and another supervisor reviewed the list and approved the firing. Hernandez sued for retaliatory discharge, claiming the harassment complaint sparked the heightened scrutiny of his work.
At trial, the company argued that retaliation was impossible because two others reviewed the supervisor's reasons for firing. But the appeals court rejected the company's argument, saying that retaliation could have occurred because those "reviews" were too superficial to be meaningful.
The other manager and HR conducted only a cursory review of the list. Instead, a qualified technician should have considered Hernandez's performance and advised HR whether those mistakes justified termination. (Hernandez v. Spacelabs Medical Inc., No. 02-35615, 9th Cir., 2003)