For the benefit of people reading this threadShe told us we would not win with the DoT sadly.
She said the ONLY way we would get anything was with a good faith gesture. She did contact some of her back channels to try and get us something via good faith. While she was waiting on those responses, thankfully, I continued to persist on my own and eventually won our claim despite her stating we would not win our case with the airline based on her previous experiences with airlines and this rule.
DoT isn't consumer oriented. A claim wouldn’t have done anything. There is enough wiggle room enabling an airline to escape responsibility for the airlines confusion.
The OP was attempting to fly to a European city, connecting in Paris, on a European airline. The "goodwill" payment is what he was entitled to under EU regulations. He was denied boarding despite having the required documentation. EU doesn't give airlines an out for being confused.
The "goodwill" payment eliminated the need to file a complaint, appeal and possibly paying someone to handle the appeal process.
Evidently the consumer advocates didn't think to file an EU claim