An unidentified man punched Regis Meliodon, a lawyer for one of the defendants, in the face during a break in the trial and then fled.
The trial will pick up again on Wednesday with statements from the defence and prosecutors.
The assault underscored the strong emotions surrounding the 2011 tragedy, which sparked outrage in Israel after the pair fled to France.
Eric Robic, who has confessed to being behind the wheel at the time, faces charges of aggravated manslaughter and not providing aid to a person in distress.
He could be jailed for 10 years and fined 150,000 euros ($187,000) if convicted.
The passenger, Claude Khayat, stands accused of the lesser charge of not providing aid to a person in distress and faces a possible 75,000-euro fine.
Lee Zeitouni, a 25-year-old pilates instructor who was crossing the road to get to work on the morning of September 16, 2011, was killed when she was hit by the 4X4 driven by Robic.
Witnesses said the car was travelling at approximately 100 kilometres per hour (62 miles per hour) in a zone where the maximum speed limit was half that.
The two men had just left a nightclub where they had consumed alcohol, according to witnesses.
They did not stop after the accident and immediately fled to France, prompting a huge outcry in Israel.
Pressure mounted on France to return the men to Israel to face trial, but France does not extradite its citizens outside the European Union.
Robic testified in court that he had drunk vodka and whisky that night and was driving above the speed limit.
He said he never saw the victim coming because his view was obscured by a truck but he felt the shock and "saw the body flying" in his rearview mirror.
Co-defendant Khayat said he was a "coward" for fleeing the scene. "But I was afraid," he told the court.
Both men apologised to the victim's family.
Then French president Nicolas Sarkozy vowed the family would get justice if a trial took place in France but stood firm against extradition, sparking a diplomatic spat with Tel Aviv.
The victim's family, who has travelled to France for the trial, would have preferred it to have taken place in Israel, their lawyer said.
"But this is better than nothing and they have arrived with confidence," added the lawyer, Gilles-William Goldnadel.
He described Robic as a "habitual road criminal" who showed "rare cowardice" in deciding to flee the scene.
The lawyer said it was "fortunate" that courts have been harsher on what he termed "road criminals" in recent years.