If you think some special situation — for example, the spouse acting as an agent — might apply, document it in writing and preserve the document in your file. (lawyerist.com)
Remember there is a duty to preserve documents when you have a reasonable expectation of legal action. (xactdatadiscovery.com)
Case law has established that a duty arises to preserve documents when a complaint is received or when litigation is probable. (d4discovery.com)