"We thought we were going home after Game 6," he said.
Montague was there, the sixth game of the 1986 World Series between the Boston Red Sox and the New York Mets, as the right field umpire for an up-close view of a play that lives on in sports infamy.
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The Red Sox were ahead, the bottom of the 10th inning with two out and a man on second, when Met Mookie Wilson hit a ball toward first-baseman Bill Buckner.
"Unfortunately, the ball was hit down to Billy. I think it would've been a close play anyway," remembered Montague. "I think it would've been a race to the bag with Mookie Wilson, so I think Billy was trying to peek and cheat a little bit so he could get over there."
The ball went through Buckner's legs.
While the Mets celebrated, Buckner hung his head and walked to the dugout. Montague retrieved the ball, and put it in his pocket before giving it to a Mets official, who auctioned it off for charity.
"I'm watching ESPN early in the morning and it said a record amount for a baseball, it just went for $93,000, the ball that went under Buckner's legs," said Montague.
"Charlie Sheen was the actor who bought it," he remembered.
Buckner went on to have a very successful major league career, a career .289 hitter with the Red Sox, Cubs, Dodgers and Angels.
A native of Vallejo, he lived in American Canyon and graduated from Napa High School, where he was inducted into the school's sports hall of fame.
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In 2012, ABC7 News interviewed Buckner's sister Jan Murphy about her brother's legacy.
"We all make mistakes, but we forgive," said Murphy. "If you are a professional athlete, you are not always forgiven so easily."
"I worked the 2004 series when Boston won and all was forgiven then and they welcomed Billy back which was great because he had a great career," said Montague. "He was a great ballplayer, so he should be remembered for that, not just one error."