The psychology of people in high pressure, threat to life situations, is fascinating, a huge chunk of people freeze or do the most ridiculous stuff.

Well worth reading "The Unthinkable" by Amanda Riley, for an interesting overview. Though there is tons of academic literature on the subject.

I actually asked a bunch of psychologists about this. Most people will either freeze or run. If your inbuilt reaction is to run, you are already in the lucky group. The goal is to use it, if possible, while running, so I tried to make it as simple as possible to activate. Unfortunately, because of Apple restrictions, you still need to launch the app, but I'm experimenting with things like using notification center for faster access