The assumptions made are not reasonable, which dramatically alters the results.
Putting this in context in any year there are typically:
6500 crashes involving EMS/ambulance
3100 crashes involving fire trucks
It's harder to get crash numbers for police vehicles, but they have around 300 police-involved traffic fatalities every year. If we estimate based on the national dataset of all crashes, about 0.5% of crashes are fatal. That means about 60,000 police vehicle crashes every year.
So, we can estimate around 70,000 emergency vehicle crashes per year in the USA. The number of Tesla-involved crashes appears to be 11 over a ~3 year timeframe. So we're comparing against 210000 overall emergency vehicle crashes.
While that sounds like it makes sense in reality it doesn't.
Tesla is being investigated because they're hitting parked emergency vehicles in freeway conditions. That's not "210000" emergency vehicle crashes, that's a small fraction of vehicle crashes. There are stats out there on fatalities of emergency responders during work on freeways. It's a disproportionate part of the fatalities from all vehicle involved accidents related to emergency services. But it's disproportionate specifically because of the higher death rate per accident than other types of accidents.
I mean Ambulances frequently are involved in accidents when they cross intersections against the lights - when is a Tesla ever autodriving in that circumstance? Fire truck accidents with fatalities frequently involve the truck rolling over - not something that is triggered by a Tesla or any other car hitting the truck. By far the largest portion of all emergency vehicle accidents involve accidents with the vehicle in motion (not directly the same but accidents are during emergency response for Ambulances at over a 60% rate and fire trucks at over a 70% rate). Police cars are frequently involved in accidents during pursuit. Autopilot is hitting parked emergency vehicles and that's a very specific sub-set of all accidents.
Autodrive is primarily used on limited access freeways (estimates are that over 90% of all miles driven by autopilot are on such freeways). The vast majority of emergency vehicle accidents involve moving vehicles in most case not on the freeway. Freeway accidents are less common per mile than other accidents. Autodrive is not driving Teslas on busy city streets or other areas where emergency vehicles are most frequently in accidents.
It's certainly possible that just recognizing that is enough to break the math. Teslas could be a disproportionate portion of the accidents involving stopped emergency vehicles on freeways. I didn't find the stats on how common those accidents are, largely because the stats are focused on how disproportionately fatal they are. Emergency responders are at their most vulnerable working on freeway emergencies. Police, fire fighters and medics, and tow truck operators are all struck and killed or struck and severely injured at a greater rate in that type of accident (many accidents not in that context are more dangerous for the other vehicle).
I did not review the underlying report, but this summary is useful.
https://www.arnolditkin.com/personal-injury-blog/2018/february/statistics-on-emergency-vehicle-accidents-in-the/ here's one on fatalities (could not review their underlying report)
https://www.respondersafety.com/news/struck-by-incidents/2019-ersi-struck-by-vehicle-fatality-report/So anytime an analysis starts by over-counting the occurrence rate by including a large number of events that occurred in situations where the test condition does not apply (i.e., including a large number of non-freeway accidents where autodrive is not engaged, and then assuming an even distribution on autopilot usage of 50% despite that autodrive usage is highly correllated with freeways where the relevant accidents occur and ignoring that in most cases autodrive is monitored by an active driver that may be "saving" autodrive from itself), it makes me question their conclusions. Are they just not deep thinkers? Or, do they have a purpose in what they present?
So, based on those numbers 0.005% of emergency vehicle crashes involved a Tesla on Autopilot.
But what percentage of the relevant crashes involve a Tesla on autopilot? It could be a significant number. If you look at the ERSI link, they analyzed the 44 emergency responders killed in roadway accidents in 2019. Check out this quote from the NY Times:
The new investigation comes on top of reviews the safety agency is conducting of more than two dozen crashes involving Autopilot. The agency has said eight of those crashes resulted in a total of 10 deaths.
https://www.nytimes.com/2021/08/16/business/tesla-autopilot-nhtsa.html While that doesn't prove anything, as it may not be comparing apples to apples, it is easy to see why autopilot crashes on the Freeway could be of particular concern if there are less than 50 responders killed by them in an average year. Even adding 5 a year for a vehicle that the authors claim is 0.28% of all vehicles on the road, where there is still a human driver monitoring them most of the time, would be evidence of a massive problem. Given that the Tesla reported statistics do not include any situation where the human driver intervened and overrode autopilot to slow down, it is actually possible that the Tesla autopilot crashes involve an alarming percentage of the Teslas where the autodrive was the
only driver paying attention.
The US has about 275,000,000 vehicles. So, take the 785k Teslas, a bit more math: Tesla represents 0.28% of vehicles on the road.
If we assume Autopilot is used half the time, we can therefore estimate that a "fleet average" vehicle is ~30x as likely to be in a crash with an emergency vehicle when compared to a Tesla on Autopilot. Probably need to further reduce that based on a weighted average of Tesla fleet share over the same timeframe, which likely would reduce it to somewhere around ~20x.
And see, building fault upon fault they get to an a conclusion that has little actual value. Claiming 50% usage when the usage is directly correllated to the type of driving, which is directly correllated to the type of emergency vehicle accident, without any attempt to rationalize those, makes the claims virtual nonsense.
So Tesla with autopilot could in fact be "30 times less likely"to be in an accident with an emergency vehicle (which is actually doubtful) and at the same time be 50, 100, 250 times (who knows really) more likely to be in an accident with a parked emergency vehicle on a freeway.
That difference is why its being investigated.
You should also take a look at this article, which is pro-Tesla but points out that the safety numbers may not be all they appear:
https://www.forbes.com/sites/bradtempleton/2020/07/28/teslas-arent-safer-on-autopilot-so-researchers-calling-for-driver-monitoring-may-be-right/?sh=5f279471d739 This was my source on the claim that over 90% of the autopilot's miles driven are on freeways.