I don't know the definite answer but in this case it must have to do with the Bobcats' total salary. They have the lowest payroll in the NBA. At one point last season they were under the minimum NBA salary floor. If they did not sign a player they would have to give every player on the roster a bonus to reach the floor. The Bobcats have space to absorb a bigger contract. Usually teams are close to the salary cap not the floor.