The couple attended the annual costume party thrown by Heidi Klum and Seal in west Hollywood on Saturday night (31Oct09), but they were reported to have become embroiled in an argument after they left the event.
Witnesses claimed to have seen the pair bickering, with one photographer telling the New York Post, "She was mad. She jumped in the front seat and (Doug) was holding her around the neck saying, 'Relax, relax.'"
The fight allegedly reached a climax when Hilton's phone was tossed out of their car window, leaving the heiress wandering up and down the road looking for the device.
But a spokesperson for the star is adamant the incident has been "grossly misrepresented," admitting Reinhardt threw the phone - but didn't mean for it to go out the window.
The rep tells ETOnline, "(The incident was) blown out of proportion by the paparazzi. Doug had thrown Paris' phone to a friend inside the car and it went out of the window by accident.
"Paris was annoyed with Doug because she was afraid that the paparazzi would get her phone. There was never a choking incident."