A track vehicle that parked close to the pitlane entrance during Chinese Grand Prix qualifying posed a low but still unacceptable risk, Formula One race director Charlie Whiting has said.
The Briton, world champion in 2009 and a director of the Grand Prix Drivers' Association, questioned why the session was not halted.
Two other incidents, a crash involving Manor's Pascal Wehrlein and Nico Hulkenberg losing a wheel off his Force India, brought red flags out.
"It must be emphasised that this is not a normal run-off area and the risk was low, unacceptable nonetheless," Whiting told Reuters in an email.
"No flags were shown because this was not on the track.
“The driver of the circuit vehicle that decided to park in the run-off area of the pit entry was rather silly and he moved it very quickly,” Whiting added.
"The driver lacked experience and won’t do it again.
"It was in no way comparable with the incident involving Hulkenberg, whose car had stopped on the side of the track with a wheel bouncing around all over the place," he added.
Whiting also clarified why marshals placed tyres at turn 14 after the second of the three sessions and then removed them again before qualifying resumed.
"The marshals thought that qualifying had finished," he said.
"I suspect that when we told the clerk of the course that we would not be continuing Q2 (the second phase which was red flagged) he thought we meant qualifying in general.
"It was quite amusing to hear all the team managers calling to wonder why we were doing this," he added.
"I confess I did wind one of them up by saying that we were getting fed up with drivers abusing the kerb and decided to take a drastic measure to deter them."
Image: Racers drive past the grandstand during the warm-up lap of the Chinese Grand Prix (Image used for representational purposes)
Photograph: Reuters