This article from the Walla Walla Union-Bulletin discusses the problem of a quorum of a public body going on a trip (in this case, to Arizona). They cannot discuss agency business or it would be a violation of the Open Public Meetings Act.
It's possible that they did not discuss agency business, as they assert, but it undermines the public's trust in them by having to believe that they spent days together and never talked about the one thing they have in common: agency business.
NOTE: The story quotes Greg Overstreet of Allied Law Group.