Logan Sargeant was "predominately to blame" for the lap 5 collision with Valtteri Bottas that ruined both drivers' Japanese Grand Prix, but the Williams rookie was nevertheless "surprised" by the Finn's move.
The pair were approaching Suzuka's Turn 11 hairpin on the restart after a Virtual Safety Car period, with Sargeant running ahead of Bottas.
But the Williams driver locked up as he entered the corner, while Bottas steered his way around the outside.
Sargeant never made the apex and understeered into the Alfa's path, clipping the latter's left-rear wheel and sending Bottas into the gravel trap.
The Finn eventually rejoined the track, but the damage sustained by his car as a result of the clash forced him to call it a day on lap 7.
"The car was undriveable," admitted Bottas. "It must have had some damage in the suspension. We also had a hole on the sidepod, so it was not really driveable.
"I tried to make the move from the outside but they locked up and ended up taking me out."
Sargeant also carried on after the incident and lasted until lap 22 when Williams opted to retire the American who had also crashed in the first segment of qualifying on Saturday.
"It was a hectic first few laps for sure," commented Sargeant. "I locked the second I touched the brakes.
"I was never going to make the corner and I was surprised he just cut underneath me, but it was just front locking from the second I hit the brake."
The stewards ruled that Sargeant was "predominantly to blame" for the skirmish as they felt that "Bottas left plenty of room for Sargeant while he came alongside."
In addition to a five-second time penalty, the stewards also added two penalty points to Sargeant's Super Licence.
"Today there was not a lot I could really do," said the young American, whose future with Williams seems more in jeopardy with each passing race.
"Two penalties, both cars had damage, just move on," he concluded.