"I thought it was a good move until the mistake he made," he said. "Last lap of the Indianapolis 500, I wouldn't expect him to lift at that point.
"He was sort of getting alongside," he recalled. "I think his front wheels and my rear wheels were alongside. He put me in a position that I had to go wide. As I said, the only mistake was when the car got loose. Maybe that's experience. Maybe the car was just bloody oversteering ... He was relying on the balance of the car as he turns in the corner.
"He made a good move. I wasn't very happy about it," the Scot admitted. "He's very aggressive. I think he thought that was his chance. I mean, why not? I think he did everything right up until he lost the rear end of the car."
The drivers with the closest view of what happened were Scott Dixon and Tony Kanaan, who had themselves both just been overtaken by the surging Sato in the final moments of the race. They sided with Franchitti in the view of the last lap incident.
"I think toward the end there, the three of us were all a little bit comfortable with each other, apart from Sato was a little bit wild, typical guy that wants to win this race so bad," said Kanaan, who was team mates with Sato in 2011 at KV Racing.
"It was a tough one," added Dixon. "I didn't expect Sato to come through on me on that second to last lap. He threw it in, I had to move up a little bit.
"Dario definitely had a good run, Sato came a little late," continued the Kiwi. "It was brave. Dario gave him room. He was so close to pulling that off. I think if he didn't pinch it as much and maybe moved up on Dario a little bit more, it would have been okay."
Dixon added: "Dario did a great job to save it. Sato, I don't know why he didn't wait a little longer. I really don't." The ensuing yellow flag after Sato's crash meant the race ended under a caution before Dixon could execute his own plan to take the race win.
The winning car owner, Chip Ganassi, also backed his driver and pointed out that Dario had it covered even if Sato had pulled off that initial overtaking move.
"It didn't really have me worried because going into turn 1, I thought we'd have a shot at him on the back straightaway or coming to the start/finish line. I wasn't overly concerned," Ganassi insisted. "I knew [Sato] had a good car, a good engine. He's a formidable competitor. I knew he had the right engine [but] I wasn't worried."
Sato's car owner, 1986 Indy 500 winner Bobby Rahal, was backing his driver equally strongly following the crash.