Cy3

Hypothetical question of course . If i were rear-ended and it was at a low enough speed where the only noticeable sign were the popped out head-rests and a dime sized license plate mark on my rear bumper; Could the STAR tool at the dealer have a record of this?

What if, in the same scenario a non-clearable warning light came on, such as, "pre-safe functions limited see owner's manual". Would there be a comment in the tool about not only what exact functions are limited but also what caused said error?

Hypothetically hoping that its just a reset that needs to occur....

stale-bread

It is quite possible. The same error came on with my distronic during heavy icing on the front of the grill. The distronic could no longer "see" throught the build up. Next day after ice cleared it was no longer showing in my dash. If you have the dealer reseat the headrests, there very well could be a note in the service history.
My coworker is looking to reseat his 09 c class head rests that have the same issue. It requires some sort of 16volt connected to the mechanism in the seats. He saw a video on youtube about this. What I'm trying to say is if you take to to another shop they may be able to reseat the headrests and clear the code and it may not be logged as an accident if thats your concern? You may also be able to do this yourself if you want to attempt it. Good luck!