One more point...
Sleuth has the key point to both the Newhall and Miami tragedies: Mindset.
Just to be clear, I am not trying to discredit any officers or agents involved.
At the time of the Newhall incident, the California Highway Patrol were primarily traffic officers. They are certified 'peace officers' in the state of California, but their duties are primarily traffic code violations. They were ready to identify suspect drivers, issue warnings or citations and if need be, physically take custody of a violator. The officers knew that, the CHP administration knew that and that was the way it was.
They were not mentally ready to shoot and possibly kill someone.
The FBI agents in Miami suffered from the same mindset - or lack thereof. They were ready to find the bad guys and arrest them. Not one of those agents on scene backed away or ran. But they didn't have it in their heads they might have to shoot and possibly kill anyone.
Sleuth has mentioned they were all armed, but not in a state of 'preparedness' for action. To me, that's the key. It's that knowledge of 'this could be the day'.
In the spirit of transparency, Sleuth and I are colleagues and friends of long standing. We've argued these incidents, agreed on them, disagreed on them and incorporated the serious and ugly lessons. I am happy to report it seemed to have worked. We got out alive.