As we reported here Tiffany Startz, 22, was at a party when her pal Jimmy Mounts, 28, promised anyone who accepted a punch from her.
John Powell, 25, took on the challenge and as the crowd gathered round someone filming it shouted
"Get this shit on YouTube!"
The busty, 22-year-old then took off her ring and socked him in the head with a closed fist punch that caused Powell to take a few steps back and his head to snap back.
Walking away, he said: "Wow nice job," but he collapsed moments later, but although he was rushed to hospital he was pronounced dead on arrival.
The judge found, after hearing expert witness testimony, that the force of the punch - which did not even leave bruise - had not killed Powell but in fact the 'impulse' or change in momentum which caused an artery in his neck to burst.
According to the Chicago Tribune Edward Burmila told the court: "There is no question defendant Startz acted negligently in this case. But negligence does not equal recklessness."
After the verdict, Tiffany's mother Theresa Startz told the paper: "Nobody wins here,' while her father Tim offered condolences to the Powell family saying it was a 'horrible, tragic accident they feel horrible about."
Powell's mother Theresa Guy told reporters her worst nightmare had come true and that she believed Startz "got away with murder."
She added that she will file a civil lawsuit against Startz and pursue a law in memory of her son so that similar acts may be prosecuted for murder.