After the conclusion of the race, USAC officials ruled that Unser had passed cars illegally while exiting the pit area during a caution on lap 149 (of 200).

The race was officially part of the 1981–82 USAC season; however, most of the top entrants participated in the 1981 CART PPG Indy Car World Series.

In response to a spectator fatality in the infield in 1980 (the result of an overturned Jeep),[11] track management decided to take deliberate steps to curtail the revelry in the infamous "Snake Pit".

On Saturday May 9, rain delayed the start of pole position time trials until 3:34 p.m. An abbreviated session saw only 9 cars finish qualifying runs.

A. J. Foyt was the fastest of the nine, sitting on the provisional pole at 196.078 mph (315.557 km/h), lightly brushing the North Chute wall and continuing without incident.

Bobby Unser took the lead into turn 1, and pulled away from the field, with Johnny Rutherford moving up from row 2 into second place.

[citation needed] When Rick Mears pitted on lap 58, fuel began to gush from the refueling hose before it had been properly connected to the car.

Meanwhile, Mears' fueler, covered in burning fuel, waved his arms to attract the attention of the fire crews already converging on the scene.

[citation needed] Thanks to quick action by Bill Mears and the fact that methanol produces less heat than gasoline, no one was seriously hurt in the incident.

Safety crews quickly surrounded the car and used the Jaws of Life to extricate Ongais, who suffered a concussion and badly broken feet and legs.

By that point, Andretti started having a tire leak, which caused him to eventually lose second place to his teammate, Gordon Johncock.

Bobby Unser celebrated his third Indy 500 victory (also 1968 and 1975), while Mario Andretti was lauded for charging from 32nd starting position to a 2nd place finish.

In victory lane a satisfied Bobby Unser made no mention of a controversy about his win when interviewed by ABC's Chris Economaki.

In a taped interview with Chris Economaki three hours after the race ended, Binford announced that he would be reviewing the video of lap 149 with the board overnight and that based on what he saw, Unser was likely to get penalized for the passes.

[30][31] It was later revealed that commentators Jim McKay and Jackie Stewart had provided the lap 149 incident commentary in post-production, and did so with the knowledge that a protest of Unser's actions was in the works.

He went about 7...8...9 cars in front of me..."[32] It was followed by the previously recorded interview with chief steward Tom Binford with Chris Economaki, with the assertion that video would be reviewed overnight, and that Unser was likely to be penalized.

That night, the traditional Victory Banquet was held at the Indiana Convention Center in downtown Indianapolis, with Andretti the new guest of honor.

Ted Koppel's Nightline focused the evening's program on the controversy and included a live interview with Andretti who compared the situation to the 1978 Italian Grand Prix, a race in which he won on the track, but was stripped of victory when officials deemed he jumped the start.

[21] Bobby Unser countered that he understood that, as long as the car stayed under the white line and in the apron, the place to blend in was the exit of turn two.

Binford, the chief steward, stated that he did receive a complaint after lap 149, but that track observers had missed Unser's infraction, so he was powerless to act during the race.

An official of the USAC board told reporters 3 hours after the reinstatement of Unser's win: The appeal panel said that, since the violation could have been detected at the time it was committed, a one-lap penalty after the completion of the race was too severe.

In its decision, which resulted from a 2-to-1 vote, the panel said that race officials had "a responsibility to observe and report illegal passing in yellow flag situations and they failed to do so."

After a final rejected petition to the Automobile Competition Committee for the United States, the American branch of the Fédération Internationale de l'Automobile, Andretti did not pursue the matter any further.

"[48] Bobby Unser, who felt the entire ordeal was politically motivated by his USAC enemies,[3][4] became disillusioned with auto racing[49] and took a sabbatical from driving.

A claim was even made at the time that Andretti "threw away the winner's ring" when he heard that Unser was reinstated the victory, but the story appears to have been fabricated.

In a 2001 interview with Jack Arute and Bobby Unser on ESPN Classic's "Big Ticket", Andretti confirmed that he kept the ring by wearing it during the appearance.

In recent interviews, Unser said that he and Mario were very close friends until that race, and while they maintained a mutual respect, they did not speak with one another for upwards of 37 years, except in a few cases where they had no choice (like at public appearances).

Both Unser and Andretti also agree in retrospect that regardless of the outcome, USAC mishandled the situation from start to finish and much of the controversy could have been easily avoided.

[52][53] During some downtime during Friday afternoon's practice session, Foyt hunted down Miller on the grass parapet along the pit lane, grabbed him and slapped him on the back of the head[54] and threatened to "remove two of [his] vital organs.

[61] The parties settled out of court for an undisclosed monetary amount, and Judge Carl O. Bue Jr. accepted the agreement and formally dismissed the suit on November 30.