1. Renders everyone that is not police, military, or government bullet&blade-proof for a limited period of time (5 days).
2. Surreptitiously communicates this fact (and the limited period) to them
3. Creates a situation that definitively demonstrates this fact to them (people are shot but unharmed)

Does the regime topple? Do the people take advantage of the situation while they can and rise above those wielding power? Or are the people so indoctrinated/beat down that they are unable to exploit their advantage and seize the government?

Can a modern totalitarian regime persist without the advantage of guns? Could an oppressed people overcome their conditioning in that short of a period of time?