Out of all the signatories, only Audrey Watters (to the best of my knowledge) posted any type of reflection about the process, and concerns with the document. Her post on what was left out and missed in the document is required reading for anyone looking to understand the larger issues around the idea of a Learner's Bill of Rights. Additionally, to the best of my knowledge, only Audrey disclosed that her travel expenses were paid by Udacity. Some of the other people who wrote about the event mentioned that the event was "convened" by Sebastian Thrun, but that doesn't get specific about who paid for them to get there. Given that some of the other signatories are local to Palo Alto, many probably didn't incur any expense, but there were enough people coming from places that require both air travel and lodging that it would be interesting to know who paid for what.