The 3 seconds it might take me to ask questions and wait for a response could be all it takes before my toddler is shot dead.

Like the 1 year old in the video? So the mother would have been justified running those cops over, right? When someone runs at me shouting with a gun drawn should I assume they just want to talk?

Police in the USA regularly shoot and kill people who pose no threat. The only threat in this situation was entirely brought by the police: they drew weapons and they put themselves in harms way by stepping in front of a moving vehicle.