How long does it take the "safety driver" to react at 65mph?
And obviously the launch is conditioned on regulators' belief that the system can handle reacting, to a degree of safety that's similar to human drivers: otherwise they wouldn't get the permit. The reaction time of safety drivers is not what this approval pivots on.
Though obviously the interesting question is: how did the company and the regulators get to this level of confidence in the system's safety
BTW, you seem to have been reading TFA as some sort of snark. It's a pretty well-established bit of internet jargon that's (at least in my experience) more winking than aggressive at this pt.