Answer based on context:

DeMarco Murray's 115 yard rushing day against the Seahawks, made him only the second running back in NFL history - next to Jim Brown - to rush for 100 yards in the first 6 games of the season. Jim Brown did it for the first six games of the 1958 season. With the victory, the Cowboys improved to 5-1 on the season, their best record since the 2007 campaign. Dallas became the first team outside the NFC West to win in Seattle since 2011. Five days after Seattle's loss at home to the Cowboys, the Seahawks traded WR Percy Harvin to the New York Jets for an undisclosed draft selection. It was reported that the surprisingly sudden move by Seattle was due in large part to Harvin refusing to return to the game in the fourth quarter. While Percy Harvin had a 46-yard kickoff return, Harvin's total yardage for rushing and receiving was -1 yard against the Cowboys. Dan Bailey's 3rd quarter 42-yard field goal made him 100-for-110 on field goals for his career, making him the most accurate kicker in NFL history with a FG percentage of 90.826% from 2011-2014. Mike Vanderjagt is second in all-time NFL accuracy with a FG percentage of 86.466% from 1998-2006. Stephen Gostkowski is a close third in NFL accuracy with a FG percentage of 86.328% from 2006-2014.

What may have caused Harvin to be traded?
refusing to return