How would "being a lot more sure" help here? If you mean the police should verify information more thoroughly before responding, then that comes at a direct tradeoff in response times. If instead you mean police should respond swiftly but not bring out the SWAT teams without more verification, then that could pose a (different kind of) safety issue for responders and potential hostages.
The issue here is more one of militarized police tactics. When you're trained to respond to any threat, any sudden move, with overwhelming deadly force, then deadly outcomes will happen.