How much is "a lot"? This seems like a couple of engineer-days if it gets down into the dirty details, which isn't huge.
Ironically, if he hasn't done any such testing, the answers would be much easier to generate. "We haven't done any." Not that the NHTSA would take it well....
I could imagine taking a week to do it, and he has 11 days.
I've been involved in writing similar descriptions to provide to NASA, and when you get down to exactly how each module works and need to enumerate every branch, it ends up being a lot of work.
He would have had 11 days to produce something. If he'd wanted to play ball, he could have produced something in the way of a response, then waited for a response to that requesting clarification, then provided more information, etc. I've dealt with similar agencies and often as long as you are being cooperative, the "clock" is fairly easy to reset.
It would appear that he didn't have any interest in cooperating at all, though. Which inevitably leads me to wonder if it's not more of a face-saving maneuver; better to blame failure on the pesky regulators than admit your technology isn't up to the investor pitches you might have made.
Ironically, if he hasn't done any such testing, the answers would be much easier to generate. "We haven't done any." Not that the NHTSA would take it well....