That moment shows the fatal flaw in Clay Varris’ whole plan, as he thinks a version of Henry without “baggage” is the ultimate killing machine.
Seeing so much of himself in Junior, Henry’s decision to not let Junior kill Clay himself, but rather take that job into his own hands, is the true change in the path of Gemini Man’s young would-be killing machine.
It wasn’t the fact that Junior was supposedly unburdened by emotional trauma that made him a good killer, but rather that he didn’t have the guidance in life to show him that there was another way.