Hey Ump: What Game Are You Watching?

Well, folks, at my place of employment, there will be drawings for tickets to certain places, mostly sports teams, and one of them is the Springfield Cardinals. The Springfield Cardinals is the Double-A affiliate of the St. Louis Cardinals. My mom won tickets to last night's game between Springfield and the Tulsa Drillers, so our family went to that game. Now let me tell you what took place. In the 6th inning, it appears to me that one of the umpires messed up. A ball, which looked like a foul ball, was incorrectly ruled fair, and all of the Springfield fans immediately booed the ump. The only question I have is this: Where was the ump's mind that night?