Romain Grosjean and Lotus will keep third on the Hungarian Grand Prix after stewards accepted that damage caused a floor infringement.
The Frenchman's car failed the mandatory 'flexi-floor' test as "the front floor deflected more than 5mm vertically when the load was applied vertically" according to a stewards' statement.
The penalty for this rules breach was potentially exclusion.
But Lotus was confident that the issue had been caused by damage.
It said that an impact with the Turn 11 kerb in Q2 had resulted in a floor support breaking, resulting in test irregularity.
The officials accepted this explanation and chose to take no further action.
The stewards' statement said:
"Based on the telemetry it was apparent that the car suffered an impact during Q2 resulting in a vertical acceleration ranging from -7.3g to +11.1g. Video evidence verified the car bottomed at Turn 11 consistent with the telemetry.
"It is considered reasonable that this impact caused a fracture in the floor stay of car #8.
"It was confirmed by physical examination that the floor stay on car #8 was identical to that on car #7 which was intact.
"'Lifing documents' (which show the history of each part) indicate the car #8 part had been fitted for in excess of 600kms including a full race.
"It is the conclusion of the stewards that the failure of this part was due to the impact in Q2 and subsequently caused the car to fail to meet the requirements of article 3.17.5.
"Accordingly this is deemed to be a case of accidental damage, not a case of non-compliance."
Grosjean will therefore retain his third place on the grid, behind Lewis Hamilton's Mercedes and Sebastian Vettel's Red Bull.
AUTOSPORT has learned that the design of floor and support has been the same since the start of the season and that Grosjean's same parts had been used and passed scrutineering throughout the Canadian GP weekend.
Lotus trackside operations director Alan Permane welcomed the stewards' decisions and praised the way they had listened to the team's explanation.
"The stewards conducted a thorough investigation, and did a good job in considering all the evidence," he said.