Helio Castroneves says he was surprised by the call from IndyCar race officials that forced him to hand the lead of yesterday's race at Detroit to Justin Wilson.
The Penske driver was leading the race with 20 laps to go when Wilson made a move shortly after a restart from a caution period.
Castroneves moved right to block Wilson against the wall and he was forced to back out of the move.
The series' competitions president Brian Barnhart ruled it an illegal block and instructed Castroneves to give the place to Wilson.
After surrendering the lead, Castroneves was unable to keep up with Wilson and second position places him 30 points behind championship leader Scott Dixon going into this weekend's finale at Chicago, rather the 20 he would have been if he'd won.
"I'm very surprised about the call," he said. "It's not something we see many times, it was unusual and I don't know why they did that.
"When he (Justin) came out of the corner, I looked and he was pulling already. I was like 'oh, wait wait, not there, let me push because my car's not bad'. I knew if I didn't do that... he had nothing to lose, he's not battling for the championship, just for a win. I think I did enough to say 'not now'."
Castroneves added that he would have been tempted to ignore the instruction had he not been fighting for the championship.
"I argued back once to Tim Cindric (his crew chief) and he said there's not much we can do. I didn't want to throw everything away because we still have one more race to go. If I didn't have anything to lose, I would have stayed there (in the lead) and appealed the decision at the end."
But Wilson felt the penalty was justified.
"Obviously, there are two sides to every story," he said. "He slid a little through Turns 10 and 11 and when he went into 12 he overshot. I went back to the inside, got some great traction, and before we even got to full power I was inching alongside him.
"I thought it was pretty straightforward and by the time we hit the brakes I'd be axle to axle and on the inside, clear cut. I was surprised he came over, then he came over more, and more to the point where I had to back out and even brake.
"It was pretty severe, I was upset on the radio and complaining to my team but they just said 'calm down, IndyCar saw it and they're going to make a call', and that's what happened.
"He was shocked he got the call, but I wasn't so shocked. There are two sides to every incident, that's just racing. If I was in his position with the championship, maybe I'd have done the same thing. I'm not trying to get in the way of the championship but I'm trying to win out there."
Castroneves was disappointed that he couldn't get the lead back from Wilson, but is determined to put it behind him and focus on next weekend's finale.
"I was pushing as hard as I could but once there were four laps to go I was thinking I'm likely to make a mistake, and Justin is a first-class guy, he's very good, and it would be difficult for him to make a mistake so I decided just to finish," he added.
"I can't let this bother me for the next race because it's next weekend. The good news is we're still battling for the championship. It's 30 points so we know what we need to do. We know we're going after a good team, but I trust my guys and I know we can do it."