Castroneves baffled by incident

The Brazilian took the lead of the race from the Ganassi driver as they exited the final corner just as the green flag was shown after a caution period.

Chip Ganassi was surprised that the Penske driver did not pick up a penalty for the move, but Castroneves said that he was not entirely sure why the pair collided.

"I don't know what happened," he said. "I really had no intention to bump him. It was just very difficult."

The Brazilian did explain why he passed Wheldon before they crossed the start/finish line though, as he felt the field were back to racing because the green flag was already waving.

"I bumped into him, and at the same time I was told 'green green green' in my ear," he said.

"You know when the green goes out, it means the race has started. That's where I say 'I'm going to have to go buddy, sorry', and I started going."

Wheldon had already struggled to get his car into the final turn before Castroneves hit him, and the eventual race winner was not sure why the British driver was going so slowly.

"I don't know if he tried to brake a little early, one of those tricks that drivers have, like a brake test to maybe upset you," he said. "Or maybe he really had cold tyres and he was just trying to be cautious."

Wheldon admitted that he was preparing to get a good run out of the corner, but he did not feel that he slowed down too much going into the corner.

"I wanted to get a good exit out of the last corner so I slowed up a bit," he said, "but Helio simply bumped me out of the way and dropped me back."