A retired Ventura, California car dealer is suing a Las Vegas Casino because he was drunk when he lost $500,000 while gambling there Super Bowl weekend. Mark Johnston is suing the Downtown Grand for continuing to serve him complimentary drinks, and loan him money when he was obviously intoxicated. Johnston has been a 'Vegas "Regular" for thirty years, and was reportedly there at the Casino's invitation.  It's a violation of Nevada law to allow an obviously intoxicated guest to gamble, and to continue serving that patron alcohol. The Casino is counter suing Johnston. He stopped payment on his casino "Markers," and is seeking damages for harm to his reputation.  A gambler filed a similar suit against a Las Vegas casino in 2009, after losing 127 million dollars.