The Indianapolis 500 book by Jack C. Fox

The 1966 Indianapolis 500 was probably the most confusing and controversial ever in the history of the race. Confusion broke out over the running order, which resulted in people being unsure, even to this day, on who won the race. The confusion in the scoring led to a controversy, wherein second place Jim Clark's team thought they were the rightful winner. Clark had spun on two separate occasions during the race, but did not make serious contact during either incident. He did not stall his engine either time, and was able to drive to the pits for the crew to inspect the car quickly both times. Clark's team contended that he did not lose a significant amount of track position, and estimated that they were still one lap ahead of Graham Hill at the finish. The scoring pylon, which was manually controlled and unofficial, changed frequently and somewhat sporadically as the scoring was ironed out, much to the dismay of Clark's crew in particular, and much to the confusion of spectators. The unofficial results at the conclusion of the race showed Graham Hill winning by 41.13 seconds over Clark. The morning after the race, USAC released the official results, and the standings were unchanged. Colin Chapman and Andy Granatelli, the entrants of Clark's Lotus team, declined to file an official protest. A possible explanation given was that the Lotus crew did not see Hill pass by Clark during the aftermath of the second spin. CREDIT: Wikipedia.