I think Ali enjoyed windng people up, esp Joe, however here Frazier obviously got serious and Ali realised maybe hed gone too far and so he comically wrestled with him and tried to diffuse the situation.
Yeah Frazier had enough of Ali's mouth. He figured he fought and beat Ali fair and square in the "Fight Of The Century" but Ali still gave Joe no credit. And I guess Ali calling him ignorant set him off.
True. And Ali was probably worried that even a minor injury,on either of them,would have cancelled their upcoming fight.