Warren Sapp stiffs waitress on a tip, then explains himself on TwitterBy Frank SchwabPeople claiming they were stiffed on a tip via social media is rivaling "stranded traveler needs a money transfer" in the Hall of Fame of hoax cliches, but nobody was kidding about Warren Sapp stiffing a waitress on a tip Tuesday.Sapp, a legendary defensive tackle with the Buccaneers and Raiders who also is legendary for being ornery at times, apparently went to a sports bar to watch the U.S. soccer team play its World Cup match. He and the other person he was with had a nice meal, with an appetizer, wings, a reuben sandwich, some Heinekens and a pizza. The bill came to $69.39. No big deal.But then the waitress didn't get a tip, and Sapp made sure the waitress knew he didn't just somehow forget it. The receipt ended up with ESPN.com's Darren Rovell.