Fall during running activity and no incident detection

With incident detection enabled for running activity I had a nice fall yesterday. Even cars stopped when they saw I rolled ower on the ground. Not a big issue just some skin bruises. However the incident (actually this was already an accident) was not detected by my watch. My phone was in my belt with me with GCM (Android) running so battery management didn't kill the app. Not happy at all...As I was a professional gymnast I handled the situation naturally easily thus when finished the roll I ended up on my feet. Do you think this was the reason why the incident detection didn't work?