Shouldn't public relations practitioners keep quiet when there's bad news that could affect the ...

As discussed elsewhere in the book, practitioners employed by publicly held
companies face ethical (Chapter 6) and legal (Chapter 15) requirements to
disclose any information that could influence an investor's decision to buy or sell
stock. Even if you put the ethical and legal requirements aside, being less than
honest is just plain bad business. The most important thing a practitioner has is
his/her credibility. Jeopardizing that credibility to artificially boost stock prices
is short sighted and, as demonstrated in this case, potentially destructive.