When an argument belongs to someone else, stay out of it.
Read: Proverbs 26:17
“Interfering in someone else’s argument is as foolish as yanking a dog’s ears.”
http://bibleresources.bible.com/passagesearchresults2.php?tp=31&book_id=24&c=26&passage1=Proverbs+26%3A17&version1=51