The Richard Childress Racing driver forced Busch down the track early in the Sprint Cup race when the two were fighting for position in the last event of their four-race probation, handed down by NASCAR after their pit road incident at Darlington.
It was a continuation of the feud between the drivers, as well as the one with Harvick's team owner, Richard Childress, who put Busch in a headlock and punched him in the Truck Series garage after last weekend's truck race at Kansas.
The incident came after Busch made contact with RCR driver Joey Coulter on the cool-down lap.
Childress was fined $150,000 and placed on probation the rest of the year.
"He knows he's got one coming," Harvick said after finishing fifth at Pocono on Sunday, two spots behind Busch. "I just wanted him to think about it."
NASCAR warned the two drivers to just race, and the battle seemed to settle down after that.
"It seemed like he was trying to make it awfully difficult on me," Busch said. "There were a couple of times I had to back off and wait (before passing)."
Busch said what Harvick did simply showed his character.
"It's not my fight," Busch said. "He's trying to turn it into one."
Busch and Harvick were placed on probation last month after a post-race incident at Darlington. Harvick, upset that Busch wrecked him late in the race, climbed out of his car, went to Busch's car and took a swing at the Joe Gibbs Racing driver who was parked right behind him.
Busch responded by driving his car forward, pushing Harvick's car into the pit road wall.
Busch said he had no option because reverse was gone in his car. NASCAR placed both on probation and fined them $25,000 each because the incident put crew members and officials on pit road in danger.
The probation ends on Wednesday.
"I'm done, man," Busch said. "I've forgiven. I've moved on."
Harvick apparently hasn't.
"It's all free game now," he said. "The race is over."
David Newton covers NASCAR for ESPN.com. He can be reached at firstname.lastname@example.org.