Lee is the last Red Sox player to miss time during the season for his military obligation after being on active duty in the Army Reserve from June 1 to October 1, 1970.

He gave up a two-run home run to Tony Perez on an eephus pitch with a three-run lead in the sixth inning of Game 7.

However, the game is remembered for the final out of the sixth, when Lou Piniella of the Yankees was tagged out at home by Red Sox catcher Carlton Fisk.

The collision between Piniella and Fisk instigated a fight between the two players resulting in a bench-clearing brawl, during which Lee suffered a torn ligament in his pitching shoulder.

[10] During the 1978 season, Lee and Red Sox manager Don Zimmer engaged in an ongoing public feud over the handling of the pitching staff.

Zimmer then relegated Lee to the bullpen, and management traded Hall of Famer Ferguson Jenkins and Bernie Carbo.

Lee won 16 games for the Expos in 1979 while being named The Sporting News National League Left Hander of the Year (over Philadelphia's Steve Carlton).

"[2] He berated an umpire for a controversial call in the 1975 World Series, threatening to bite off his ear and encouraging the American people to write letters demanding the game be replayed.

[4] In his 1984 book The Wrong Stuff, he claimed his marijuana use made him impervious to bus fumes while jogging to work at Fenway Park.

His propensity to criticize management led to his being dropped[citation needed] from both the Red Sox and the Expos, and the end of his professional career by 1982.

After the Expos released Lee in May 1982, he played for semi-professional teams, including the single-season Senior Professional Baseball Association in Florida, largely composed of retired major leaguers.

[17] Since 1999, Lee has been an ambassador for Major League Baseball to Cuba helping to bring Cuban players to the US and setting up goodwill tours especially to Canada.

In June 2008, Lee pitched for the Alaska Goldpanners during the annual Midnight Sun ball game played at night during the Summer Solstice.

[19] In September 2010, Lee pitched 5+1⁄3 innings for the Brockton Rox (a team that was then a member of the Canadian-American Association of Professional Baseball), picking up the win.

He also makes frequent appearances on Sports Overnight America, a nationally syndicated radio program hosted by Gerrie Burke (a long-time friend) out of San Francisco.

[25] A large portion of the wine project’s proceeds go to support Inner City Youth Baseball and the Red Sox Scholars programs in New England.

[27] In 2003, filmmakers Brett Rapkin and Josh Dixon joined Lee on a barnstorming trip to Cuba, gathering footage for the documentary film Spaceman: A Baseball Odyssey.

In 1988, Lee was the Rhinoceros Party presidential candidate running on a platform of bulldozing the Rocky Mountains so Alberta could receive a few extra minutes of sunlight and banning guns and butter.

[30][33] During the campaign he advocated for a Canadian style health care system, revealing that he got his shoulder surgery in Canada for $5000, estimating it would have cost $50,000 to $70,000 in the US.

He is the author of four books, two written with Richard Lally, and two with Jim Prime: Lee appears as a minor character in the 2021 Serge A. Storms novel Tropic of Stupid by Tim Dorsey.