The incidents in the comic of Savage Banner were caused by a "failsafe" subconsciously set up by the Merged/Professor Hulk to render himself powerless if his anger rose to a level that would release the Savage Hulk persona. 
  Scenes of Banner acting Hulkish cited in the TV series or post-series movies are just showing the Hulk's mentality preceding the physical metamorphosis by seconds as the transformation begins.