RELATED: Untold stories of Earnhardt’s ’98 win | The meaning of a pennyA few days after the 1979 Daytona 500, Donnie Allison’s wife, Pat, called him to the phone.“Hello?” Allison said.He didn’t recognize the voice on the other end of the line, and the caller didn’t identify himself, saying simply, “They have a film that shows the wreck. Make ’em show it to you.”“Who is this?” Allison insisted.“They have a film that shows the wreck,” the voice repeated. “Make ’em show it to you.”Click. The line went dead.The wreck in question — and its aftermath — put NASCAR racing on the map. On the doorstep of what would have been a career-defining victory in the 1979 edition of the Great American Race, Allison saw his winning chances evaporate in a last-lap wreck with Cale Yarborough, as the drivers were dueling for the lead on the backstretch.With Allison and Yarborough out of commission on the infield grass, Richard Petty came from a half-lap down to win the Daytona 500, the first NASCAR event that featured live flag-to-flag coverage on television.As Petty rode to Victory Lane with his crewmen draped over his car, Yarborough and the Allison brothers —Donnie and Bobby — brawled near the backstretch.Track emergency workers try to break up a fight between Cale Yarborough, Donnie Allison and Bobby Allison. | ISC Images & Archives via Getty ImageTo this day, Yarborough contends that Allison ran him onto the infield grass as Yarborough was attempting to pass for the lead. Allison, understandably, sees it differently.“I don’t care what anybody says, Cale Yarborough or anyone else, that SOB wrecked me,” Allison said in January, on the night he was inducted into the National Motorsports Press Association Hall of Fame. “No question.”“You don’t wreck somebody from the front. The guy in the back lifts the gas if he doesn’t have somewhere to go. I didn’t run him in the apron. He ran himself in the apron.”Initially, NASCAR saw the wreck the same way Yarborough did. All three drivers were fined $6,000 for the fist fight, but the Allisons were placed on probation.“Bill France Jr. came over to me, and he said, ‘Now, Donnie, you should have let him have the apron.’ I said, ‘Billy, I didn’t put him in the apron—he put his damn self in the apron. He hit me in the back first.’France disagreed. “The film doesn’t show that,” he said.“I don’t give a damn what that film shows you,” Allison replied. “I’m telling you what happened.”The probation didn’t sit well with Bobby Allison.“Bobby was infuriated, so he appealed it,” Donnie said.The appeal was scheduled between races at a Red Roof Inn in Atlanta. The day before the hearing, Donnie got the mysterious phone call.NASCAR executives Les Richter and Bill Gazaway were among those hearing the appeal. Gazaway asked Bobby to wait in a room across the hall while Donnie viewed five different films of the wreck.The third film showed the initial contact between the right front of Yarborough’s car and the left rear of Allison’s.Donnie Allison’s car sits just off the track following a last-lap crash in the Daytona 500 NASCAR Cup race at Daytona International Speedway. | ISC Images & Archives via Getty Images“The first contact, it went on by, and I said, ‘Can you back it up in slow motion until I tell you to stop,” Donnie recalls. “I’ll never ever forget what happened if I live to be 200 years old. Les Richter popped out of his chair and said, ‘Why in the hell haven’t we seen that film?’“End of appeal. Bobby never came back into that room. We met in the hall. They put Cale on probation.”The combatants were able to recoup their fine money at a rate of $1,000 per race for five races—for maintaining good behavior. Donnie got all but $1,000 of his money back. Bobby claims NASCAR still owes him $2,000. But Donnie isn’t sure Bobby didn’t get repaid.“He said he didn’t,” Donnie said. “I think he did. He’ll tell you a story about a lot of things, but you better watch it.”One thing is certain. The phone call remains a mystery.“Till today, I don’t know who it is,” Donnie said.One other thing is certain. Regardless of the circumstances and the truth about the details, NASCAR wouldn’t be what it is today without the wreck in the 1979 Daytona 500 and the fight that followed. That’s a point of view the Allisons and Yarborough can agree on.