When it comes to baseball’s unwritten rules, it’s often imperative that umpires are apprised of any history that might play into potential confrontation between teams. Frequently this helps. Sometimes it doesn’t.

Wednesday fit into the “doesn’t” category.

As the Red Sox and Orioles took the field, everybody around baseball—fans, players, coaches and all levels of management—knew about what had gone down between them. Also, more importantly, what had the potential to go down.

Commissioner Rob Manfred was sufficiently concerned, arranging, along with MLB’s Chief Baseball Officer Joe Torre, a pregame conference call with Dan Duquette and Buck Showalter of the Orioles, and Dave Dombrowski and John Farrell of the Red Sox. In so doing, he put everybody on both sides on notice, and effectively provided plate umpire Sam Holbrook an extra-heavy mallet with which to hammer out the peace.

In an ideal world, the threat of action on the umpire’s part would have been enough. In retrospect, it might actually have sufficed, and yet we do not live in an ideal world. Because in the second inning, Baltimore’s Kevin Gausman hit Xander Bogaerts.

In a vacuum, the play would barely have registered. Gausman had faced only five batters. He’d been erratic, throwing only eight of his 20 pitches on the day for strikes. The fateful pitch was a 76 mph curveball—the last weapon of choice for somebody with vengeance on his mind. Given that Gausman was working under the hottest lights imaginable for such a thing, Bogaerts could not have been hit less intenationally.

It made no difference. The game had, somewhat surprisingly, begun without warnings, and Holbrook opted against issuing one to Gausman. Instead, he ejected him from the game, in the process becoming the poster child for brain-locking umpires who make shortsightedly stupid calls.

The Orioles were stunned. Gausman signaled furiously that it had been a breaking pitch that failed to break, and nothing more. Catcher Caleb Joseph spiked his mask and had to be physically separated from Holbrook. Adam Jones ventured all the way in from center field to protest, and was eventually tossed when he kept yapping following a fifth-inning at-bat.

So the Orioles had to go to their bullpen three outs into the game. Even though they were fortunate to squeeze seven innings out of Richard Bleier (making his first appearance of the season after being called up from Triple-A Norfolk) and Ubaldo Jimenez, they will be pitching shorthanded in the bullpen for days to come. Also, they lost, 4-2.

We’ve seen pitchers tossed for similarly little. We’ve seen instances in which clueless umpires didn’t do enough to staunch a potentially volatile situation. But as we learned Wednesday, it’s not just the information an umpire’s given, it’s how he uses it that matters.