Well no, thats like telling someone To rob a store because if "you don't get caught, You won't be in trouble." if He did something to deserve it then technically it would be retaliation.
I hit my little brother all the time, When he was 3-4 He wouldn't get out of my princess tent thing (i was only like 6-7) So I hit him in the back as hard as I could...And he started bleeding out of his nose, I thought I killed him because he was bleeding. But he's fine...I think