Maybe. Maybe not. Not all people freak out when something bad happens. Some dissociate, and feel nothing.

I know because that happens to me. I have had a few experiences in my life where it would have probably been normal to get at least a little bit hysterical, but I didn't because I really felt nothing at all. I could think, I could even act, I started to process what I could do, and then did that (not much).

And then freaked out several hours later, when everything was well over. Had some nightmares too, for some months.

The whole thing is said to usually come from some sort of childhood trauma, usually something that happened more than once so the child learned to mentally escape when she could not do it physically (not that I remember anything that might match in my childhood). Often enough the people who go there are unable to do anything, and don't necessarily really even see what is going on, they go a bit catatonic. But there are different reactions with that. What it feels like to me when I do that is that I start to observe the whole thing kind of clinically. It stops feeling real, becomes more like watching the news, or a movie or something, except one that I am not emotionally connected to. I merely observe.

If that woman is like me, she probably dissociated the second she heard the shots, realized what was happening, thought "historical moment, I better get video" and started filming. And maybe then spent the next night shaking and crying in her bed.