Jacob looked at Axel as he walked away. His hand remained in the air long after Axel has walked through the door. It was a symbolic gesture that Jacob would never lower the hand of friendship, no brotherhood to Axel. Eventually the gesture had to end it was time to head back so Jacob called for the nurse.
While the nurse was helping to guide Jacob to physical therapy he kept playing Axel's words over and over in his head.
"Fighting through Hell can turn even a Spartan into a Demon."
"So far, I've never killed another human being. I'm not about to start now." He stopped at the exit, glancing over his shoulder. "Especially one of my own. Good day, Chief."
Jacob knew the end result of this. Jacob knew that Axel had no intention of ever going that far but no one ever does. Evil and hatred are long journies we take through our own souls. What one day seemed so absurd and far fetched we soon relaize becomes habit. Axel did not kill Spike just physically beat him close to the point then stopped. Jacob wondered how many times Axel could stop himself before he did take that final step down the path of darkness even hurting the ones who cared for him most.
Jacob stopped hoping Axel was still in hearing distance. Looking back over his shoulder he shouted one thing to Axel "Abbra"
Then he went in for physical therapy.