This is my opinion when it comes to these legal questions. Research these things either through your personal attorney or at least look for a specialized attorney on the web. One the best resources for this is Ed Greenberg of thecopyrightzone.com
. Ed Greenberg and Jack Reznicki have published a book, now in its second edition that will answer about any question regarding copyrights and releases.
IIRC, Ed's reply to a question of do you need a model or property release, is if in doubt or do not know, then yes you do. It's always better to get one and not need it, than later on need one and not be able to get one.