Public understanding of the 'public domain'

Last Tuesday 17th April i went to my first Own-It event – ‘Dead or Alive: Whose art work is up for grabs?’ – and was very happy to see a roomful of artists and creative types discussing the ins and outs of copyright law.
I was however kinda surprised to hear their IP-expert solicitor use the phrase ‘public domain’ to indicate something entirely different to our use. He did not use the phrase to indicate an intellectual creation free from legal restraint but rather to indicate the inverse of private, as in publicly available works; works that have been published. Then an audience member asked about the rights-status of works in the ‘public domain’, and the expert answered with reference to published works, suggesting he did not associate the term with freedoms.
Seems the legal profession do not understand the term ‘public domain’ in the same way our community does, something which had not occurred to me. Guess i figured it was a recognised legal concept, whereas its more an emerging notion. Should we then revise our project name before going public?