My dad blowed up over drinks

So my dad ask my sister for a drink after he done eating and my sister fully fill his cup, not to the brim btw, just normal full. He later blow up calling my sister disrespectful and me, the oldest daughter also got yelled at for some reason. He claimed my sister didn't fill his cup to a full when he asked for a drink earlier therefore what she did was a sign of retaliation. Retaliation of what you ask? I don't have a fckin clue. My mom, my sister and I all looked at his direction, confused with what hg meant and when my sister said how does filling up his drinks equate to being disrespectful, he lost his temper. He yells and slammed the table while calling my sister dumb. He later started to get petty and tell us how hard it is for him to check our house locks every night, which took him like 3 minutes to do. And most of the time I already locked it.

Well to be fair we didn't like him, as he's manipulative as all hell and sometimes it does slip out in between our performances while serving him. I guess he got a hint that we hate him and now insecure about it? My mom love him tho, she would defend him, said he didn't know better and use his sickness (kidney failure), saying that's the cause of his behavior. But really he's been like that before he's sick anyway. Idk how my mom looked at my dad, knowingly manipulative, having bad temper, did hit us until we bleed and decided to have 6 children with him. Cuz if it's me I'll be disgusted.