Replay definitely the right call
Without a doubt, baseball's GMs got this one right.
Most umpires fail to consistently get the balls-and-strikes calls right, let alone boundary calls.
But that is part of the game, and it's up to pitchers and hitters to adjust to the strike zone.
As for boundary calls, I remember a game at Camden Yards in 2003. White Sox third baseman Joe Crede clearly hit a home run down the left-field line, but it was ruled foul.
I also remember former Sox manager Jerry Manuel catching all kinds of heat for declining to come out of the dugout and argue the decision.
Manuel's point was that he could have argued until he was ejected and the call would have remained the same.
Under this new proposal, boundary calls should be up for review. Maintain the human element for everything else.
Also, allow only one minute for a decision to be made. Baseball games are long enough as it is.