Try this: Forget about everything you know about his conversation, what you think about us, the game.
Now read this:
"Bully-someone who hurts or frightens someone else, often over a period of time, and often forcing them to do something that they do not want to do"
Now read, without any bias, OP, and tell me: would you not describe his actions as bullying?
Just stop there, don't take it further.
Now, you might believe that he was in every right to do that an play like that. move nevertheless to pray on weaker player, when you gain nothing in game terms an he loses something. move of his game character, of course - in RL he just pressed buttons - nothing wrong with that.
What you did is just as smart as taking the diccionary definition of life & ending all phylosophical & scientific discussions on it.