Report: Arbitrator rules DeSean Jackson owes Drew Rosenhaus over $500,000

New Redskins receiver DeSean Jackson will have to allocate some of the money from his new contract with Washington to pay off a debt to his former representation. According to Jeff McLane of the Philadelphia Inquirer, an arbitrator ruled Tuesday that Jackson owes $516,415 in back loans and fees to agent Drew Rosenhaus. Rosenhaus filed…