Marussia's sporting director Graeme Lowdon was surprised Sergio Perez got away without a penalty following his clash with Charles Pic during final practice at Austin.
Perez made contact with the Marussia driver some 20 minutes into the session, spearing the Frenchman's car at Turn 7 after leaving his braking too late.
The crash, which the stewards deemed was a racing incident, damaged the floor of Pic's car.
Lowdon believes it was clear that Perez was at fault.
"It looked to me like a guy driving into one of our cars," Lowdon told AUTOSPORT. "Our car was in front, you could clearly see it. It's a big enough track and he was in full control of his car.
"So it's a bit of a surprise they ended having a collision."
Lowdon revealed the damage to Pic's car was more severe than initially thought, and said the mechanics had to work flat out to get the car ready for qualifying.
He also believes the incident had compromised Pic's work.
"It was really unfortunate for Charles, because it pretty much ruins what we can learn on the car from that session, because the floor was completely ruined," he said.
"It was a real tight job to get that car back in qualifying condition for qualifying. It could have ruined his qualifying as well. The mechanics had to an amazing job making sure it was put back together.
"There was a huge amount of damage. It didn't look like it when we finished the session and it compromised Charles's weekend.
"I only saw the replay once but it's surprising to see. That said, the stewards have access to all that stuff and they made the decision, and that's what it is."
Despite the problem, Pic qualified in 20th position, behind team-mate Timo Glock but ahead of both the Caterhams.