Aloma said Barrymore followed the other vehicle and got its license plate number, which she then handed over to sheriff's deputies.
She said she didn't know the extent of damage to Barrymore's car.
No arrests had been reported Tuesday morning.
"It could be dangerous," Aloma said of following someone after an accident.
Still, she emphasized that getting a license plate number is instrumental to tracking down a hit-and-run motorist.
Barrymore's screen credits include the "Charlie's Angels" movies, "Fever Pitch" and "E.T. the Extra-Terrestrial."