But the Sydney Morning Herald said Stewart didn't escape the incident without some damage – namely, a black eye.
Stewart's public relations representative confirmed to SB Nation the driver has left the country and was "simply questioned about the alleged incident."
"After the questioning, he returned to his hotel, got a good night's rest and is currently en route to the states," Stewart spokesman Mike Arning said via e-mail. "No charges were filed."
However, SpeedCafe cautioned Australian police are not done with their investigation – even though Stewart was allowed to depart Australia.
SpeedCafe posted a statement from police, attributed to the local commander:
A 39-year-old man was arrested at the scene and was taken to Parramatta Police Station after a 46-year-old man was allegedly struck in the face by a racing helmet.
The 39-year-old man was released by police without charge, pending further investigation.
Stewart is 39 years old.
The Morning Herald reported Stewart struck Sydney Speedway co-owner Brett Morris with his helmet after a heated discussion, and Morris struck back "leaving Stewart nursing a black eye."
Sydney Speedway did not respond to requests for comment. The track's general manager brushed off the altercation in comments made to SpeedCafe.
SpeedCafe reported Morris had yet to be formally interviewed by police.
However, it's hard to imagine Morris would press charges against Stewart; the American driver was heavily promoted on the track's web site and in the media as a featured attraction at Sydney Speedway. And if Morris doesn't want to pursue the matter, the case will likely be closed.
Stewart's large fan base is made up of many people used to hearing about his temper, but who support him anyway. On Facebook, several fans seemed to cheer the news.
"Give them hell Smoke," wrote Kathy Gartman.
"wow doesnt surprise me..we hoosiers tell it like it is..love you smoke ♥," wrote Linzee Mundtt.