I'm not sure what word would be better since "after" carries the same implication.
"whistleblower" is a journalism word meant to imply who the good guy is and endow them with credibility. Rewriting the story with "employee files complaint" doesn't hit the same.
If this is really the evidence you think they're using I'd be willing to bet you didn't read their report: https://live-whistleblower-aid.pantheonsite.io/wp-content/up...
Sure, it's all anecdotal -- it is testimony, after all -- but much of it is backed up by email and text conversations. On the topic of a potential conflict of interest, what do you think about the personal relationship between Doug Elmendorf and Elliot Schrage?