Who’s in the wrong?

My dads cousin (who I was also very close with) took his life a week ago and my dad has been sensitive ever since, while he was passing through the channels he was so mad when he passed the spanish channels saying “this is America why do they have spanish channels it makes no sense!” He was acting really irrational about it and kept saying things “the only person in this house that speaks Spanish is (my grandmas name)” “how do we remove the spanish channels, I am colombian and white and my dad is white and so I finally decided to say “thats not nice, grandma speaks Spanish, she was born and raised in Colombia” he replies “but she speaks English here! It’s America”, and the argument goes on for me trying to defend my abuela and he then proceeds to say “look just drop it, I’m really upset about (his cousins name”.” But I made the mistake of saying “I’ll drop it, I don’t know why you think you can say offensive stuff like that just because your upset” He got so mad, and my mom told me to be quiet so I did and left the living room and went to my room. Why does he have to share his thought out loud when they aren’t nice. My abuela likes to watch her spanish tv we share cable on 2 tvs, why would he want to take it away?! That’s her first language, any language can be spoken here in America! He’s now using the fact of his cousins passing to be a little bit abusive like he was before. Before all this he was verbally abusive and things, and I thought this whole thing with his cousin being depressed and taking his life would change him, but no, he’s using that as an excuse to be disrespectful to my culture and my grandma. If my grandma heard what he said she would cry.