Like I said, I would have done what the people at the first stop in the other car did.
Fleeing and alluding is dangerous, I wouldn't recommend it.
Do you often stop for threatening unmarked vehicles
About as often as I seize federal buildings.
Maybe you think Finicum was stupid enough to not realize he was dealing with LEO. I have no reason to make that jump with you.
When he was pulled over he saw two options, go to jail, or flee.
After he crashed while fleeing he saw two options, go to jail, or die.
"...just go ahead and shoot me." - Finicum
When he was pulled over he saw three options, go to jail, get shot where he was (along with the women) [since someone was shooting at his truck], or flee.
The rest of your post is smoke.
There is no requirement for the peasantry to stop for unmarked vehicles.
In fact, law enforcement usually recommends that you proceed to the nearest police station.
Which Finicum was apparently trying to do, bygoing to see the Sheriff.