Does witnessing violence leave you all shaky?

Just saw an altercation developing in a convenience store parking lot between two men and a woman. The woman seemed the most upset, screaming and she kept shoving the men apart, even though it didn’t really look to me like either of them was out for the other guy’s blood. I got out of there and called the convenience store and said, “You have a situation developing in your parking lot.” I’ll ask them later what it was all about.
It’s been a half hour since I witnessed it, and I’m still a little shaky. Is that some sort of instinctive reaction, or am I just a pansy?