Jarno Trulli said he had no choice but to overtake Lewis Hamilton in the incident that cost the Italian his third place at the Australian Grand Prix.
Trulli finished in third position for Toyota, ahead of Hamilton, but the FIA stewards gave him a 25-second penalty after the race, deeming he had overtaken the McLaren driver while the safety car was on track.
The disappointed Toyota driver, who had started the race from the pitlane, claimed Hamilton left him with no choice but to overtake him.
"I can't say how disappointed I am to finish third but have the result questioned," said Trulli.
"When the safety car came out towards the end of the race Lewis Hamilton passed me but soon after he suddenly slowed down and pulled over to the side of the road.
"I thought he had a problem so I overtook him as there was nothing else I could do."
Team boss Tadashi Yamashina, whose team had already being sent to the back of the grid over a technical infringement, admitted today's penalty was very frustrating.
Yamashina was nonetheless encouraged by his team's performance.
"This is an extremely frustrating way to finish a challenging weekend," he said. "Already we were disappointed to be starting from the pitlane after we were informed yesterday about the problem with our rear wing.
"We responded to that in a fantastic way and we showed that our car has genuine performance."