Williamson was put on administrative duty after being caught on video speeding the wrong-way down Highway 321 in Catawba County.
Carisa Lynn shot the video showing Williamson driving his HP car on the other side of the divided highway and says it was terrifying to watch from her side of the road.
"It wasn't safe at all. I mean, I would rather have a car blow by me at 150 miles an hour than a police car coming straight at me at 70 or 80 miles an hour," Lynn said.
But a driver trailing the group of speed-racers told a 911 officer he was convinced they would cause a wreck if they weren't stopped.
Another driver who called 911 stayed on the line, describing the racers stopping and starting along the road.
"We're getting a lot of calls on it," the operator told Danielle Holliday. "That's why I want to keep you on the line."
"I understand the video of the trooper going the wrong way has made a lot of people furious," Holliday told the I-Team, "but I wish I had video of what these guys were doing and I think people would see both sides of the coin and realize that he did the best thing that he could do at that time to get these guys stopped."
Seven people were charged in connection with the street racing.
Troopers seized five BMWs last Sunday after motorists called to report a group of people blocked traffic to race along U.S. Highway 321 in Catawba County.
All seven were charged with impeding traffic. Five of the seven also were charged with prearranged racing.
Williamson had been employed with the NCHP since 2016.
The Associated Press contributed to this report.