I am not sure where you have the idea that because robbers are after money at a store that anybody else considers themself worry free. Robberies are always dangerous for those present in such situations.
Where this might be more relevant is in looking at where compliance works or not. Everybody complied but the clerk Sam who claimed to not speak English. He didn't comply and it appeared to piss off the robbers and the two on the ground got shot even though they were complying. Of course, the robbers may have been planning on killing everyone anyway. Who knows?
In about 13% of the cases, folks who comply still get harmed. That means that in about 87% of the cases, compliance does work. This is just a great example showing that compliance on statistically means you will most likely come out without physical harm, but that statistics don't mean squat when you are one of the few that end of harmed or killed.