Other countries don't need resource to calm angry crowds because baton is enough to dispel the crowds. Why? Because those nations employ stricter control on gun. It is different with the criminal organizations that relies on black market. That shows those governments have tightened controls to make harder for criminals hence black market.
For USA, never mind the accidental shooting, from the angry crowds to criminals, it is all same for police enforcement. It is hard to tell apart from the civilians with guns to criminals with guns. Police will have respond the same way. In result, some misunderstanding occurs which comes at the expense of the defenseless civilians sometimes.
Don't take my words. Ask American polices directly. Many occasions they have admitted that ever since the gun rights, polices have never been cautious and to the extent, it makes their jobs harder than before. Ask police directly.