NASCAR responded appropriately to the error it made by owning the error, admitting and saying they were going to investigate further. Ultimately the outcome of the race was not affected and rain came as well to end the race early, so both of those things helped NASCAR not look as bad as they could have, but it was human error and they admitted it openly.
I believe NASCAR officials did respond appropriately to the phantom yellow caution light that ended the Food City 500 at Bristol Motor Speedway. Their response is part of their job and the decisions they made were based on experience within NASCAR. There is no reason to question their decisions, they can't be changed at this point anyway.
Yes, I think that NASCAR officials responded appropriately to the phantom yellow caution light that ended the Food City 500 at Bristol Motor Speedway, because NASCAR is dangerous. People die in NASCAR. Officials were right to error on the side of caution, because it may have saved a life in the end.
Although they say it was a stupid error. This gaffe highlights the need that if something like this happens and there is a need to reset the field and rerun those laps that were lost due to a caution flag error. It is unfair to the crowed and the drivers to not allow for them to race to the finish when there is no liability on the track.