Yes, it can be a bundle of reasons, thats good you changed your interactions.I have been working with my rooster and he hasnt done anything further aggressive with me. I realized all this was happening during treat feeding. I have changed how I interact with him and he seems to be more respectful of my space.
i know some people that repeatedly pick up the roo, and if he bites they pick him up (to tell him your the boss) this is pretty bad, because hes telling them no. lol