WRT your trainee, there are other ways to interpret their actions than through the lens of race. For example, they want to be sure they are doing what is right, given conflicting information from multiple sources of authority.
If I were witnessing something I thought was ethically and legally wrong, you’re darn right I’d want to make a call and be sure. You, as the trainer, should be praising them for doing exactly that. On these matters, you want people to be /sure/, not to guess. I am a trainer myself, and my motto for these kinds of decisions is NEVER GUESS — LOOK IT UP! This isn’t the time to be inventive and creative.
The people you should be truly upset with are those other physicians in charge who have allowed the police to mistreat patients in past, and set a terrible precedent. That’s where your problem truly lies.