Brian BarnhartIndyCar Series boss Brian Barnhart (left) staunchly defended the penalty given to Helio Castroneves for blocking his Penske teammate Will Power at Edmonton.

Castroneves was stripped of victory for defending his lead at a restart with three laps to go, and confronted several series officials after the race. But Barnhart was adamant that the penalty was justified.

"It's really disappointing that it comes down to something like this," Barnhart said. "In a situation like that, as officials we're just reacting to what's happening on the racetrack. We don't create the situation, we respond to it.

"The rules are clear on it. In every drivers' meeting we talk about it. On road courses we divide the track physically in half, and from the braking point to entry they're told you can only be on the inside half if you're attempting to overtake someone.

"If you're on the inside half while someone is trying to overtake you, it's blocking. Unfortunately... I know they're competitive guys and it was late in the race, but it really wasn't a difficult call to make.

"It is what it is. The rulebook states the penalty for blocking is a minimum of a black flag drive-through penalty. It's a shame it comes down to that, but as officials we just respond to the situation presented to us. And we respond according to the rules."

Power said that Castroneves had defended the lead on the inside and pushed him wide, but believes the penalty on his teammate was too severe.

"Helio had the inside line, I tried to go around the outside... I understand Helio's position – he's leading at a late restart," Power said. "I got a run on him, he blocked me. I would say a black flag is a pretty harsh penalty, but it is what it is. It was just one of those racing things. When you're leading on the last restart you want to keep the lead."

Scott Dixon, who was running third at the time of the incident, took second from the delayed Power at the next corner, and inherited the victory following Castroneves' penalty, was not surprised by the decision.

"Brian always says that if you're blocking going into any corner and you are on the right side – especially into Turn 1, you're going to get a penalty," he said. "We get told every week, so you could see something was going to happen.

"Obviously, Will had a pretty good run. The only way to stop him was blocking. So if that's what you call it, yeah, that's blocking. [It's] pretty strange to not lead a lap and actually win the race."