The sidepod of Nick Heidfeld’s Renault exploded as the German retired from the Hungarian grand prix.
A fan’s video posted on Youtube showed a marshal being struck by the debris and limping away, and Swiss newspaper Blick said it is "unclear whether the man was injured" badly.
Veteran Heidfeld admitted he has "never seen anything like that before" and that he was scared.
"I had a fire in Barcelona, but I wasn’t worried there at all -– but this one got quite close. This time I felt the heat, so I had to get out quickly," said the German.
As for whether he is hurt, Heidfeld confirmed to Auto Motor und Sport: "No, nothing happened to me."
And he joked to Bild newspaper: "I’m not burned — my suit was black even before I got in (the car)!"
Renault team boss Eric Boullier however appeared to blame Heidfeld for the incident, insisting that the car is "not designed to stay running (during a pitstop) on high revs for so long".