18 laps to go, Gordon is pushing Kahne for the lead and trying to make him use enough fuel that he can't make the finish. A car deep in the field stalls and seems not able to make to the pit so a yellow comes out. During the caution the pace car comes out and the field does about 4-5 laps behind the pace car, conserving fuel so likely Kahne can make the finish. During the laps behind the pace car, Gordon doesn't stay behind Kahne, but pulls along side of him, possibly forcing Kahne off line and into the marbles. Right before the restart Kahne tells crew chief "tires are filthy" Upon restart Kahne seems to have lost the speed he had before the caution and falls to 5th. Could Gordon have intentionally forced Kahne into the marbles causing debris to stick to the tires resulting in loss of traction? Did Gordon break the rules by not staying behind Kahne during the pace laps?