Bruce interrogated by S.H.I.E.L.D.
Diplomatic action
S.H.I.E.L.D. tracked
Bruce Banner to Michigan, where
Nick Fury insisted on going personally to speak to him, to detirmine his threat level.
After speaking to him, without admitting who he was, Fury had his agents pick a fight with Bruce, deliberately triggering a transformation. Seeing that Hulk was more interested in escape than escalating the violence, Fury detirmined that it was safer to leave Bruce at large, rather than trying to contain the Hulk against his will.