•The 44-year-old failed to apply the regulations correctly in a safety-car period at the end of December's final Grand Prix in Abu Dhabi.
•This led to the Dutchman, 24, passing Britain's Lewis Hamilton when the race was restarted for one final lap.
Former race director Michael Masi says he received death threats following the controversy that saw Max Verstappen claim his debut world title last year.
The 44-year-old failed to apply the regulations correctly in a safety-car period at the end of December's final Grand Prix in Abu Dhabi.
It led to the Dutchman, 24, passing Britain's Lewis Hamilton when the race was restarted for one final lap.
Mercedes' Hamilton, 37, had been on course to win an eighth world title.
"There were some dark days," Australian Masi told News Corp.
"Absolutely, I felt like I was the most hated man in the world. I got death threats. People saying they were going to come after me and my family."
An inquiry by motorsport's governing body, the FIA, found " human error" was responsible for the incorrect application of the rules in the 2021 title decider.
A first world championship victory for Verstappen denied Hamilton a record eighth title.
"They were shocking," Masi, who formally left the FIA earlier this month, said of messages he received on Facebook. "Racist, abusive, vile, they called me every name under the sun.
"And they kept on coming. Not just on my Facebook but also on my LinkedIn, which is supposed to be a professional platform for business. It was the same type of abuse."
Masi says he just "wanted to be alone" as he tried to deal with the aftermath. "I didn't want to talk to anyone," he said.
"Not even family and friends. I only talked to my close family - but very briefly.
"It did have a physical impact, but it was more mental. I just wanted to be in a bubble. I had no desire to talk to them. I just wanted to be alone, which was very challenging. "The whole experience has made me a much stronger person."