I disagree, the NHTSA is responsible for determining safety. Given that the two extremely unusual 'catastrophic' cases last year resulted with owners stopping the car and exiting safely, one could not logically claim this was a safety issue. Every other country's NHTSA equivalent that has investigated this has cleared Tesla.
This is by choice, because Elon feels this is the right thing to do for peace of mind. They have enough margin in the cars to absorb this cost.
The NHTSA is concerned with what
could happen as well. You can be damn sure that if there's a reasonable fix or mitigation for a flaw they'll insist that manufacturers add it.
But the NHTSA is sensitive to PR issues and will try to avoid recalls if possible. To me this is a classic private agreement.
- Risk was already relatively low
- Tesla stopped the lowering, providing empirical evidence that the risk depends on ride height and/or time of year
- Tesla (possibly with NHTSA assistance) has identified ways further to reduce the risk from collisions
- Tesla changes its software to give fine-grained control to drivers
(- Tesla's lowering might not be quite as low as it was?)
- Tesla agrees to make the changes available to all drivers on request or at their next service
- NHTSA is satisfied that altogether the existing safety systems and the new measures will reduce the risk sufficiently and doesn't force a R****l.