The face of Bill Bixby's stunt double is easily recognizable during the last fight scene at the burning oil well.
During the transformation into the Hulk at the burning oil well, the back of the Hulk's jacket shows several small cuts where the jacket was scored to facilitate ripping apart.
After David Hulks out the second time, following the fight over the explosive detonator, the wires used to for the Hulk to 'throw' David's assailant are seen as he crashes into the shack.