About $400 million was bet on the National Football League game worldwide, said RJ Bell, chief executive of the pregame.com website, which reports on the sports-betting industry.
About $150 million more was bet on Green Bay than on Seattle, so the referees' call resulted in a $300 million swing toward the sports bookmakers, Bell said in an interview.
Green Bay was leading 12-7 and covering the spread until the controversial calls that resulted in a 14-12 Seattle victory. The NFL has locked out its regular referees in a union contract dispute and is using replacements from lower football levels whose mistakes had met heavy criticism even before Monday.
"The far-reaching effect of all this is that obviously the replacement referees issue needs to be resolved ASAP because the National Football League cannot have any more egg on their face like they did last night," Marc Lawrence, publisher of the Playbook.com website, said in a telephone interview.
Lawrence estimated $250 million to $500 million had been bet on the game worldwide, the majority on Green Bay in part due to the team's popularity and because fans often bet the favorite on Monday night football, Lawrence said.
Bell said that before Monday, the replacement referees had offered an "extra variable" that - if anything - had increased interest.
"The bookmakers want there to be a perception of fairness," Bell said in a telephone interview. "If it feels random and there are added variables like an official's bias for home teams or an official's bias to call extra pass interference penalties, that is stuff that a handicapper can handle."
In Monday night's game, the officials had ruled that a Seattle receiver and Green Bay defender simultaneously caught a last-hope "Hail Mary" pass in the end zone, a touchdown under NFL rules. A video review did not find indisputable evidence to overturn the call, a referee found.
The NFL acknowledged on Tuesday that referees missed a clear penalty against the Seattle receiver that should have ended the game. The league said, however, that it supported the result of the video review and that Seattle's victory was final.