Re: "emergency braking switched off by design"
"Uber could have designed its software to work with Volvo's emergency system, but it didn't."
Without source code and design specs, I do not see how Uber could have integrated their AV system with Volvo's safety system. Volvo's system had to be turned off in order for Uber's to drive the car. Otherwise there would be three systems potentially trying to operate the brakes and throttle -- Uber, Volvo and car operator.
* Uber emergency braking system did not appear to exist.
* Volvo emergency braking was disabled.
* Car operator was distracted and the AV did not have an alert system.
Uber's fault but for different reasons.