Ferrari's Fernando Alonso criticised what he considered dangerous driving by Nico Rosberg in their battle during the Bahrain Grand Prix.
The Mercedes driver was cleared by race stewards who investigated two incidents in which he appeared to push Alonso and McLaren's Lewis Hamilton off the track.
"If instead of such a wide run-off area there had been a wall, I'm not sure I'd be here to talk about it," said Alonso.
Rosberg said he preferred not to say anything until he had seen a replay.
Hamilton also refused to comment. He had clashed with Rosberg on lap 10.
After Hamilton, the 2008 world champion, pulled to the inside of Rosberg out of Turn Three, Rosberg defended his position by moving towards him, right over to the white line that demarcates the edge of the track.
Hamilton was undeterred, continuing to push and eventually overtaking the German.
The incident with Alonso was almost identical but happened on lap 24. Unlike Hamilton, the Spaniard was not able to pass the Mercedes.
Article 20.4 of the F1 sporting regulations says: "Manoeuvres liable to hinder other drivers, such as deliberate crowding of a car beyond the edge of the track or any other abnormal change of direction, are not permitted."
After the incident between Alonso and Rosberg, Alonso went on team radio to accuse his rival of an illegal move.
"He pushed me off the track," said the two-time world champion. "You have to leave a space. All the time you have to leave a space."
After the incident with Hamilton, Rosberg claimed the Briton had overtaken him off the track, a manoeuvre not allowed in the rules.
Ruling on the Alonso incident, the stewards cleared Rosberg of wrongdoing.
"At the time Rosberg made the move, Alonso was behind him and no part of his car alongside the Merc," they said. "Rosberg made the move to the right before Alonso.
"For more than half the distance travelled by Rosberg in moving in a straight line towards the right edge of the track, Alonso remained behind him.
"Because the speed delta (difference) between the cars was quite significant it was difficult for Rosberg to detect the exact position of Alonso in relation to his own car. No part of Alonso's car was alongside Rosberg."
In explaining their verdict for the Hamilton incident, the stewards used almost identical phrasing.
After learning Rosberg would not be punished, Alonso wrote on Twitter: "I think you are going to have fun in future races! You can defend position as you want and you can overtake outside the track! Enjoy! ;)))"