Hardy Rodenstock (born December 7, 1941 in Marienwerder (Kwidzyn), legal name Meinhard Gorke ) is a former publisher and manager of pop and Schlager music in Germany and is a prominent wine collector, connoisseur, and trader, with a special interest in old and rare wines. He became famous for his allegedly uncanny ability to track down old and very rare wines, and for arranging extravagant wine tastings featuring these wines. It has been alleged that Rodenstock is the perpetrator of an elaborate wine fraud. In 1992, a German court found that Rodenstock had "knowingly offered adulterated wine" for sale.

In May 2008, a book about the controversy was published under the title The Billionaire's Vinegar, written by Benjamin Wallace. In the book a tritium test and two carbon-14 tests date the wine circa 1962. Later, a cesium-137 test gave similar results. Rodenstock was not available for comments on the publication of the book. Auctioneer Michael Broadbent, on the other hand, was unhappy with how his relationship to Rodenstock was portrayed in the book.  In July 2009 it was announced that Michael Broadbent would sue Random House, the publishers of The Billionaire's Vinegar, for libel and defamation of character, on claims that the book made allegations that suggested that Broadbent had behaved in an unprofessional manner in the way in which he had auctioned some of these bottles and that his relationship and dealings with Hardy Rodenstock was suspected of being improper. The suit was filed in the United Kingdom, whose libel laws are favorable to the plaintiff. Unlike U.S. law, in English defamation law even true allegations can be defamatory. Random House initially stated it did not believe it had defamed Broadbent and would defend the lawsuit.  In October 2009, Random House, avoiding trial, entered into a settlement agreement with Broadbent. In a statement read out in open court, Random House apologised unreservedly for making the allegations, and accepted that they were untrue. It gave an undertaking not to repeat the allegations and paid Broadbent undisclosed damages. It removed the book from sale in the United Kingdom. It also was reported that Wallace was not a party to the lawsuit or settlement, that Random House would be making no changes to the book, and that it would continue to publish the book in all territories except the UK.  The film rights to The Billionaire's Vinegar have been purchased by a Hollywood consortium, while HBO simultaneously had bought the film rights to the corresponding The New Yorker article.Answer this question using a quote from the following article:

Why did he choose to sue?
on claims that the book made allegations that suggested that Broadbent had behaved in an unprofessional manner in the way in which he had auctioned some of these bottles