No, the reduction in deaths was through not crashing.
The airline industry would not have got safer faster by deliberately doing more crashing. "Okay, we need to increase safety, so let's crash as much as we can!" is something they didn't say, because that wouldn't have made any sense.
What you've done here, and the reason you've been upvoted to the top spot, is you've applied the Silicon Valley mantra of "failure is good" to airlines, and by extension, to autonomous cars. That mantra isn't really even true for software - it's not that failures are good, it's that learning is good - but it just about works in a world where people turn can turn free VC dollars into Medium posts and acqui-hires by failing, and hence where you might as well learn that way, rather than proceeding slowly with painstaking care; this approach doesn't really work in worlds where failures are underlined in blood.