This was my impression as well, in that what I've read suggests Tesla is making claims on the basis of percentage chance of injury from NHTSA data, but NHTSA do

This was my impression as well, in that what I've read suggests Tesla is making claims on the basis of percentage chance of injury from NHTSA data, but NHTSA does not take a position on whether differences in those percentages is significant. I can't say I've verified the percentages myself though, nor do I have the requisite understanding to say whether there are margins of error present (which would make Tesla's claims correct but potentially statistically meaningless.)