It appears, from the article, that they're working on a shoestring budget. My initial impression was that adding at least one full-time specialist, maybe more,

It appears, from the article, that they're working on a shoestring budget. My initial impression was that adding at least one full-time specialist, maybe more, simply to dot the i's, cross the t's for NHTSA, plus purchasing (or renting) infrastructure to do all the required tests could probably easily bankrupt the project in its current state. My guess is sometimes it's probably ok to decide a project is not yet in a position (financially or structurally) to take on the additional responsibility of dealing with an enormous bureaucracy such as the US govt. And if that means you have to give your product away in order to do so, that's a calculated risk you might feel you have to take. I seriously doubt that when NHTSA contacted them they were like, "just invite us into your building and show us around", like a health code inspector might.