Concretely, they are basing this analysis on 3 Waymos being involved in incidents involving a serious injury or fatality nationwide, versus 16 for NYC for hire ones (presumably in NYC or its immediate environs). The three incidents they're referring to involving a Waymo, for reference:
>The three incidents they're referring to involving a Waymo, for reference
Article: "cause “way mo” fatal crashes" and "Waymo’s autonomous cars cause crashes that result in serious injuries"
In that case the phrasing in the OP is an outright lie. All of the examples provided don't suggest waymo was at fault. The first involved a driver hitting 6 cars in total (one of which is a waymo), and was charged. The second involved a motorcycle rear-ending a waymo. The last was a police chase that ended with the suspect crashing into a waymo. I don't see how anyone can conclude that waymo "caused" those crashes.
In fairness to the authors, legal fault is not sufficient to encompass how different vehicle types change accident risk. E.g., if someone breaks abruptly for no reason and that results in rear ending, the breaker wouldn't be "at fault," but they still share part of the actual blame. And I'm sure at least half of the accidents involving taxi cab drivers had them similarly wrong place, wrong time.
Where I object to the authors is the statistical spelunking and secret data sets that aren't publicly available but provided as a favor from NY government as a favor to the author. Are cabbies really 14x as safe as the average driver? It's impossible to say; we know nothing about the data they used to get that estimate. And some things strain credibility: what model do they suggest for Waymos being much safer than cabbies for all accidents (as supported by their own reported data), but suddenly getting much worse for serious injuries and fatal accidents, especially seeing as how all of the three accidents involving the Waymos they use involved a stationary or low speed Waymo where the Waymo is pretty clearly not at fault?
Article: "cause “way mo” fatal crashes" and "Waymo’s autonomous cars cause crashes that result in serious injuries"
In that case the phrasing in the OP is an outright lie. All of the examples provided don't suggest waymo was at fault. The first involved a driver hitting 6 cars in total (one of which is a waymo), and was charged. The second involved a motorcycle rear-ending a waymo. The last was a police chase that ended with the suspect crashing into a waymo. I don't see how anyone can conclude that waymo "caused" those crashes.