Quote 10
HIGGINS [with dignity, in his finest professional style] You have caused me to lose my temper: a thing that has hardly ever happened to me before. I prefer to say nothing more tonight. I am going to bed. (4.89)
Higgins, so used to being in control, is disappointed and frustrated to find himself losing hold of his emotions. He, the transformer, has become the transformed, if only momentarily.
Quote 11
HIGGINS. If you come back I shall treat you just as I have always treated you. I can't change my nature; and I don't intend to change my manners. My manners are exactly the same as Colonel Pickering's. (5.191)
In claiming that he can't change his own nature, Higgins complicates his own claims about change and transformation; if he can't change his nature, we have to wonder, how can he really understand how to change someone else's?
Quote 12
HIGGINS. Of course I do, you little fool. Five minutes ago you were like a millstone round my neck. Now you're a tower of strength: a consort battleship. You and I and Pickering will be three old bachelors together instead of only two men and a silly girl. (5.265)
Higgins acts as though he were waiting for Eliza's final act of defiance the whole the time; it is hard to say, however, whether his confidence is as great as he makes it seem.