i'm just sayin'
This phrase means you're not trying to start a fight and you're not even sure if the person heard you right.
'I'm just sayin' you're a f***ing idiot!' when no one was listening.
'I'm just sayin' you're a bad dancer!' when he was too busy eating.
'I'm just sayin' you're a lousy student!' when he didn't even look at me.'