Red flag or am I wrong ?

My bf and I were talking and he brings up how Muhammad Ali had to fight a longtime friend after his Parkinson’s diagnosis and how the friend beat him up. My response was “he shouldn’t have done the fight after his diagnosis” like i’m allowed to have my own opinion, well my bf got so mad and says i’m a fucked up person and my mindset is fucked up and how can i judge someone and not know the reason for him proceeding with the fight and he says how the world was so mad about it and here i am “heartless” i told him i’m not heartless and i’m not judging him for the fight just think he shouldn’t have done it and off of the information he gave me was the information i was going on and i was sticking to my opinion. Well that pissed him OFF, he kept saying how im dumb and fucked up and even punched the headboard and hasn’t talked to me since. Is this a red flag or am i wrong or missing something? literally just gave my own opinion on the situation..like i am genuinely confused