Lawful advice or obstruction of justice?

Here's an interesting development out of Vermont.  A criminal defense lawyer apparently advised her client that if the victim didn't show at trial the matter would be dropped.  Was that ordinary, lawful legal advice or a subtle coordination of an obstruction of justice?  (Hat tip to Nuts & Boalts)  suppose that if we understood the full context we would conclude that it was lawful, but somewhat "close to the line."  Does the fact that police are occasionally taping calls between lawyers and nonclient witnesses "chill" the lawyer's zeal in a way that should bother us?  Or does the occasional taping incent lawyers to cut square corners?