Unfortunately, I would deal with scenarios somewhat like this, sometimes on a daily basis - this being my choice since that's the environment within which I chose to work. However, this was with some oppositional adolescents struggling with mental health issues. They could run the gamut from Oppositional Defiant Disorder, episodes of Psychosis (typically the worst - as they're not responsible but highly explosive), and the most dangerous with individuals with Antisocial Personality Disorder (some describe as sociopaths) because their intentions are premeditated and calculated to do harm. Occurrences like this, when I say a daily basis, that would happen in "waves" as the populations would change and it would be a transient. While this population was adolescents, they do come in large physical forms. Honestly, I never saw an ethnic difference - just really angry kids. Girls could absolutely be the worst, with often lots of pent-up adrenaline and hatred in response to being sexually abused virtually always by men. A lot of men don't realize how dangerous it might be to attempt to molest a woman who's had a past history, with PTSD and they respond with a primal "fight" response.
Really glad you maintained your composure. It's not really fun to play "the flinch game".
Retirement's much better!