True about the sunglasses
I think, it also checks head position, But I agree, this is not a sure shot either.
I've not implied anything; just mentioned the possibility. Why use a proprietary method of recording these? The black boxes you mention, are they also using proprietary formats? If there is an incident, why shouldn't the driver/owner have a right to read his own car's data and download it to his computer to analyze? There were few people who repeatedly asked for their data logs from Tesla after minor incidents, which Tesla has refused.
Why proprietary formats? It's quite simple. To save space/bandwidth. If you store everything in a human readable format, you waste a ton of space.
There are 53 different (relevant) variables according to the report.
Let's just take one for example, here's the 8 possible values for the "Autopilot Hands On State" variable:
HANDS NOT REQD = Autopilot not controlling vehicle.
HANDS REQD DETECTED = Steering wheel torque sufficient to detect hands-on.
HANDS REQD NOT DETECTED = Steering wheel torque insufficient to detect hands-on.
HANDS REQD VISUAL = Visual warning to driver.
HANDS REQD CHIME 1 = Stage 1 aural warning to driver.
HANDS REQD CHIME 2 = Stage 2 aural warning to driver.
HANDS REQD SLOWING = Autopilot slowing vehicle.
HANDS SNA = Steering wheel hands-on detection not available
With a proprietary binary format you can store that variable in just 3 bits (which allows 8 values). With human readable 8-bit ascii, it would need at least 23 characters so that would take 23 bytes (184 bits). That is 61x as much space.
As for the part about regulation about car data (summary, automakers are not legally required to equip cars with EDRs, nor provide tools for retrieving such data):
"3.3. Event Data Recorder Regulations
Federal regulation 49 CFR 5637 specifies the data collection, storage, and retrievability requirements for vehicles equipped with event data recorders. The regulation does not require that vehicles be equipped with event data recorders. Equipping a vehicle with an event data recorder is completely voluntary. The regulation also specifies vehicle manufacturer requirements for providing commercially available tools and/or methods for accomplishing data retrieval from an event data recorder in the event of a crash. The Tesla Model S involved in this crash did not, nor was it required by regulation, contain an event data recorder. As a result, the data recorded by the ECU was not recorded in accordance with this regulation. Further, there is no commercially available tool for data retrieval and review of the ECU data. NTSB investigators had to rely on Tesla to provide the data in engineering units using proprietary manufacturer software."