For some reason, Li Du felt that Bradley was a pain in the neck. Perhaps their magnetic fields did not mesh well. Humans were always like that. Some people felt like old friends the moment they met, while other people just hate each other on the spot. Li Du and Bradley were the latter, especially after Bradley had ordered the helicopter pilots to cause them problems. Bradley certainly didn't feel much better about Li Du, and the two simply had to "play nice" because of each other's identities.