I wonder what happens when a police officer tries to pull one over.

I'm curious as well...are there any protocols in place for emergency services or police interactions?

Yes, there were some news stories about the challenges that public safety and law enforcement had when dealing with Cruise vehicles. The company sent training materials, but that’s as much as I can remember at the moment, I’m sure some searching would pull up hits.

Sure, to that end my favorite Cruise anecdote stems from one of the Cruise humans forcing the car to make an illegal left turn off of Mission a few years ago. Granted Cruise's software still struggles with legal left turns, but still.

A formative experience when I was learning to drive was being pulled over to the right and watching a firetruck pull behind a car stopped at a red light, siren blaring and lights flashing, and eventually having to get on the PA and tell the person to run the red light so they could get through.

That's a mistake by the fire truck. You aren't supposed to preemptively run a red light to help them, they're supposed to order you to do it right away if that's what they want.

This surprised me, and I haven’t found any information one way or the other about the universality of the rule, but I did find this guide that strongly implies you’re correct.

https://www.firerescue1.com/fire-truck-crash/articles/stop-f...

In Germany you have to make way/not obstruct, though you don't have to endanger yourself excessively. So if the traffic behaves, you absolutely have to move out of the emergency vehicle's way traffic light be damned. Usually you'd pull over to not put yourself into a prime t-boning spot, but with good visibility you actually drive across the intersection to where you where going anyways, and ensure you let them pass.