According to Rob Drake, the home plate umpire for Sunday afternoon's game between the Washington Nationals and Arizona Diamondbacks, Jason Marquis hit Justin Upton intentionally in the back in a one-run game in the sixth inning. Drake tossed Marquis from the game when Marquis' first pitch to Upton in the sixth inning went astray. Manager Jim Riggleman was later tossed as well after arguing the call.
The move came one inning after Diamondbacks starter Ian Kennedy hit Jayson Werth, causing Werth to drop his bat and stare at Kennedy. Drake issued warnings for both teams and evidently decided that Marquis violated that warning. Marquis, in turn, was very angry, pointing to the scoreboard as the reason why Drake's logic was crazy. (The fact that the scoreboard graphic is right where he is pointing in this screenshot is a funny coincidence).
Sure, the Nationals and Diamondbacks have been plunking each other all weekend, but Marquis would have to be crazy to intentionally hit someone in a one-run game to put a runner in scoring position. I happen to think Marquis is not crazy, but clearly, Rob Drake disagrees.
Here's video of the play.