NHTSA collects data if self-driving tech was active within 30 seconds of the impact.
The companies themselves do all sorts of wildcat shit with their numbers. Tesla's claimed safety factor right now is 8x human. So to drive with FSD is 8x safer than your average human driver, that's what they say on their stock earnings calls. Of course, that's not true, not based on any data I've seen, they haven't published data that makes it externally verifiable (unlike Waymo, who has excellent academic articles and insurance papers written about their 12x safer than human system).