Madison Bumgarner thinks the Cubs are lying about stealing signs

At the Giants-Cubs spring training game on Thursday, San Francisco's ace Madison Bumgarner punched out Jason Heyward on a called third strike and a few moments later it looked like they might throw down.

Meanwhile, Heyward claims he was merely looking to Fowler for confirmation that the called third strike was indeed a strike, and stayed fixed in Fowler's direction because he didn't get a response.

Just words, no punches were exchanged. Are you buying the Cubs' explanation?