Full disclosure: I am not a baseball fan*.
It seems to me a curious thing, this kerfluffel about the blown "perfect game" because it is an example of bizarro linguistics**. Despite the fact that incontrovertible evidence exists that proves the game does in fact meet the requirements of a "perfect game," the refusal of MLB to officially sanction it as a "perfect game" has caused a titanic uproar amongst fans. Why? We all know it really was a perfect game. Why does anyone care about the label that MLB puts on it? We care because they have been granted, by convention, the right to determine what counts as a "perfect game" and what doesn't. We could call it a "perfect game" amongst ourselves, but it just wouldn't be, because MLB has the ultimate say so. It's like Pete Rose. We all know he's a hall of famer, but he just isn't. Because MLB says he isn't. This is the opposite of the way linguistic items generally form their meanings. Generally if enough people agree that "wug" means X, then that's what it means. But not in this case. 300 million Americans (and several million Japanese, Cubans and Venezuelans) all agree that Armando Galarraga pitched a perfect game, but we are linguistically overruled by a governing body, and that's that.
This strikes me as a variation on Putnam's semantic externalism whereby speakers assume that a word's meaning is determined by someone else. We don't naturally see our own role in determining meaning. If there is a clearly defined group, like MLB, then it's even easier to surrender our contribution, even when our own intuition about the meaning is so acute.
It's also interesting that almost nothing rides on this label. They won regardless of what you call it; it doesn't affect the team's record at all. That label will not likely affect the team's season, except perception. The pitcher might have been able to use a "perfect game" as a negotiating tactic to get more money, but few fans care about that. He would have gotten his name in the record books, that's tangible, but again, it does nothing for the team.
*I was a wrestler for 14 years; if there's no blood, it's not a sport.
**I invented that term, patent pending, all rights reserved.