"You're always playing tricks on me."
Since fucking when? All of Rohan's appearances after his initial arc has him telling nothing but the truth and not being the least bit antagonistic aside from threatening Josuke for cheating at the dice game. If Araki wanted to convey that Rohan likes to pull tricks on people like Koichi to the point where others think he's lying when shit hits the fan a la "The Boy who Cried Wolf", I don't think he did a good enough job on that.