According to witnesses, Biffle approached Said's car after a wild green-white-checkered finish in which Said got into the back of David Ragan, Biffle's Roush Fenway Racing teammate.
The bump sparked a violent crash that destroyed the cars of Ragan and David Reutimann, whose Toyota went upside down and into a retaining wall shortly before another crash initiated by Tony Stewart brought out a caution flag and secured Marcos Ambrose's first Sprint Cup win.
After the race, Biffle took at least one swing at Said through the window of Said's Phoenix Racing Chevrolet. Once Said unstrapped himself and climbed out of the car he went after Biffle, who by then was protected by his crew.
"He is the most unprofessional little scaredy cat I've ever seen in my life,'' said an angry Said during a TV interview with ESPN The Magazine's Ryan McGee. "He wouldn't even fight me like a man after. So if someone texts me his address, I'll go see him Wednesday at his house and show him what he really needs."
"He needs a whooping and I'm going to give it to him. He was flipping me off, giving me the finger. Totally unprofessional. Two laps down. I mean, he is a chump," Said added.
Said, a road course specialist who finished 22nd, admitted it was his contact that initiated the crash that collected Ragan and Reutimann, who were released from the infield care center without major injuries.
But Said was more upset with Biffle, who finished 31st after running out of gas early, than about the accident.
"He comes over and throws a few little baby punches and then when I get out he runs away and hides behind some big guys,'' Said said. "But he won't hide from me long. I'll find him. I won't settle it out on the track. It's not right to wreck cars, but, he'll show up at a race with a black eye one of these days. I'll see him somewhere."
Biffle used his Twitter page to respond to Said's remarks.
"Boris,'the roadcourse ringer' caused that wreck," he posted on his page, later adding. "Then Mr. Class pulls in behind my truck after the race today?! Shouldn't you go check on David & David? How unprofessional & disrespectful!"
Both drivers left the track before NASCAR officials had a chance to talk to them.
"We are evaluating the situation,'' NASCAR spokesperson Kristi King said.
Any potential penalties likely would be announced on Tuesday or Wednesday.
David Newton covers NASCAR for ESPN.com. He can be reached at firstname.lastname@example.org. Information from the Associated Press was used in this report.