Did Charlie make the right decision not to intervene during the assault on Nostrils

As Norman and Charlie cut through the Fitzroy gardens, they encounter Barlow and his gang, who beat Norman until he needs hospital attention. In an act that demonstrates the themes of power, ambition, and masculinity taken to a terrible extreme, Barlow “kneecaps” Norman with a pipe, a variation on the gangland practice of shooting people in the kneecaps as punishment. I really don't think Charlie could have done anything without getting beat as well.