We'll need help from native speakers.
"The defendant's having shot the policeman reacted against him."
I don't understand this sentence. The meaning/definition of 'react against somebody/something' is this.
"The defendant had reacted against the policeman, and Mr. D(=the defendant) shot Mr. P(=the policeman)." or "The defendant, who had reacted against the policeman, shot him(=the policeman)." is understandable to me.
"His having been shot made him nervous."
="The fact that he(=the policeman, in this context) had been shot made him(=the defendant, probably) nervous."
(I think they(=the '-ing forms' in your sentences) are called 'perfect gerunds', by the way.)